IP Multicast: MFIB Configuration Guide, Cisco IOS XE Fuji 16.9.x
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Verifying IPv4 Multicast Forwarding Using the MFIB
This module describes how to verify IPv4 multicast forwarding using the Multicast Forwarding Information Base (MFIB) in multicast
networks operating in Protocol Independent Multicast (PIM) sparse mode (PIM-SM), Source Specific Multicast (PIM-SSM) mode,
or bidirectional PIM (bidir-PIM) mode.
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Prerequisites for Verifying IPv4 Multicast Forwarding Using the MFIB
Before performing the tasks in this module, you should be familiar with concepts described in the “ Multicast Forwarding
Information Base Overview ” and “ IP Multicast Technology Overview ” modules.
The tasks in this module assume that IP multicast has been enabled and that PIM-SM, PIM-SSM, or bidir-PIM have been configured
using the relevant tasks described in the “ Configuring Basic IP Multicast ” module.
Restrictions for Verifying IPv4 Multicast Forwarding Using the MFIB
You must be running a software image that supports the IPv4 MFIB infrastructure.
Information About Verifying IPv4 Multicast Forwarding Using the MFIB
Guidelines for Verifying IPv4 Multicast Forwarding Using the MFIB
When you verify IPv4 multicast forwarding using the MFIB in PIM network environments, a useful approach is to begin the verification
process on the last-hop designated router (DR), and then continue the verification process on the routers along the SPT for
PIM-SM or PIM-SSM (or on the shared tree for bidir-PIM) until the first-hop DR has been reached. The goal of the verification
is to ensure that IP multicast traffic is being forwarded properly through an IP multicast network.
Common Commands for Verifying IPv4 Multicast Forwarding Using the MFIB
The table describes the common commands used to verify multicast forwarding using the MFIB.
Table 1. Common IP Multicast Commands for Verifying Multicast Forwarding
Command
Description and Purpose
show ip igmp groups
Displays the multicast groups with receivers that are directly connected to the router and that were learned through Internet
Group Management Protocol (IGMP).
Use this command to confirm that the IGMP cache is being properly populated on the last-hop DR for the groups that receivers
on the LAN have joined.
show ip mfib
Displays the multicast forwarding entries within the MFIB.
show ip mrib route
Displays entries in the Multicast Routing Information Base (MRIB) table set by PIM, IGMP, or the MFIB.
show ip mroute
Displays the contents of the multicast routing (mroute) table.
show ip pim rp mapping
Displays all group-to-Rendezvous Point (RP) mappings of which the router is aware (either configured or learned from Auto-RP
or bootstrap router [BSR]).
Note
The
show ip pim rp mapping command does not apply to routers in a PIM-SSM network because PIM-SSM does not use rendezvous points (RPs).
Common Mroute Flags
When you verify multicast forwarding, it is helpful to start by looking at the control plane using the
show ip mroute command. The table describes some of the common flags that you will observe in the output of the
show ip mroute command when verifying multicast forwarding.
Table 2. Common Mroute Flags
Flag
Description
Mode Flags (All Routers)
S
Sparse—Entry is operating in sparse mode.
s
SSM—GroupEntry is operating in SSM mode.
B
B Bidir—GroupEntry is operating in bidirectional mode.
Last-Hop DR Flags
C
Connected—Indicates that an IGMPv2 report for the multicast group was received.
I
Received Source Specific Host Report—Indicates that an IGMPv3 report for the multicast group was received.
L
Local—Indicates that the router itself is a member of the multicast group. Examples are groups that are joined locally by
the
ip igmp join-group command , the
ip sap listen commands, and the well-known Auto-RP groups, 224.0.1.39 and 224.0.1.40.
Note
Locally joined groups are process switched.
J
Joined SPT—Indicates that the SPT threshold is set to 0 kbps and the next (S, G) packet received down the shared tree will
trigger an (S, G) join in the direction of the source.
Note
If the SPT threshold is set to infinity (using the
ip pim spt-threshold infinity command), the J flag will not be set and all (S, G) packets will stay on the shared tree.
First-Hop DR Flags
F
Register Flag—Indicates that the router is a candidate to register for the multicast group.
(S, G) Forwarding Flag (Routers Along SPT)
T
SPT-bit Set—Indicates that packets have been received on the SPT.
Pruned Flag
P
Pruned—Entry is in a prune state. Multicast traffic for the multicast group will be dropped by the router.
Common MRIB Flags
When you verify multicast forwarding, it is helpful to confirm the communication between the control plane and the MFIB by
examining the MRIB using the
show ip mrib route command. The table describes some of the common flags that you will encounter in the output of the
show ip mrib route command when verifying multicast forwarding.
Table 3. Common MRIB Flags
Flag
Description
Entry Flags
C
Connected--When set, this flag should also appear in the MFIB. For more information, see the
C Flag description in the
Common MFIB Flags section.
IA
Inherited Accept--When set, this flag should also appear in the MFIB. For more information, see the
IA Flag description in the
Common MFIB Flags section.
Interface Flags
A
Accept--When set, this flag should also appear in the MFIB. For more information, see the
A Flag description in the
Common MFIB Flags section.
F
Forward--When set, this flag should also appear in the MFIB. For more information, see the
F Flag description in the
Common MFIB Flags section.
NS
Negate Signal--When set, this flag should also appear in the MFIB. For more information about this flag, see the
NS Flag description in
Common MFIB Flags section.
Common MFIB Flags
When you verify multicast forwarding, it is important to examine the MFIB using the show ip mfib command to ensure that multicast traffic is being forwarded as expected. This section describes some of the common flags
that you will observe in the output of the show ip mfib command when verifying multicast forwarding.
C Flag
The table describes the C flag.
Table 4. C Flag Description
Entry Flag
Description
C
Connected--Indicates that the MFIB will inform the multicast control plane when it receives traffic from a directly connected
source. This flag is used for multicast groups running in PIM-SM or PIM-DM. For PIM-SM, it triggers PIM registration. For
PIM-DM, it triggers dense mode flooding.
Note
PIM-SSM and bidir-PIM MFIB entries will not have the C flag set.
C Flag Sample Output
The following is sample output from the show ip mfib command. In this example, the output has been filtered to display only entries that have the C flag set.
RP# show ip mfib | inc Flags: C
(*,224.0.0.0/4) Flags: C
(*,239.1.1.1) Flags: C
(*,224.0.1.39) Flags: C
(*,224.0.1.40) Flags: C
Well-Known Groups
(*, 224.0.0.0/4) Flags: C
This entry indicates that a directly connected check is being performed for the multicast range 224.0.0.0/4. The assumption
is that this range is in the group-to-RP mapping cache. If it is not in the group-to-RP mapping cache, this entry will not
appear. (*, G/m) parent entries, such as this entry, are used when a match for a (*, G) or (S, G) entry is not found. When
traffic from a directly connected source matches a parent entry, the appropriate (*, G) and (S, G) entries in the MFIB, MRIB,
and mroute tables will be created.
(*, 224.0.1.39) Flags: C
This entry indicates that a directly connected check is being performed for the Auto-RP Announce multicast group. When traffic
from a directly connected source matches this entry and no corresponding (S, G) entry is found, the appropriate (S, G) entry
will be created in the MFIB, MRIB, and mroute tables.
Note
(*, 224.0.1.39) appears in routers that are configured as an RP for Auto-RP using the ip pim send-rp-announce command. The C flag will always be set for this entry, whether the multicast group is running in PIM-DM or PIM-SM.
(*, 224.0.1.40) Flags: C
This entry indicates that a directly connected check is being performed for the Auto-RP Discovery multicast group. When traffic
from a directly connected source matches this entry and no corresponding (S, G) entry is found, the appropriate (S, G) entry
will be created in the MFIB, MRIB, and mroute table.
Note
(*, 224.0.1.40) appears on routers that are configured as a Mapping Agent using the ip pim send-rp-discovery command. The C flag will always be set for this entry, whether the multicast group is running in PIM-DM or PIM-SM.
Standard Multicast Group Entry
(*, 239.1.1.1) Flags: C
This entry indicates that a directly connected check is being performed for the multicast group 239.1.1.1.
Note
239.1.1.1 was arbitrarily chosen for this example to represent a standard multicast group entry in the show ip mfib output; in practice, the multicast group entries that will display in the output will depend upon your multicast network
environment and application.
For this example, the (*, 224.0.0.0/4) entry will not be used because (*, 239.1.1.1) is more specific. When traffic from a
directly connected source matches the (*, 239.1.1.1) entry and no (S, G) entry match is found, the MFIB will create the appropriate
(S, G) entry then inform the multicast control plane to do the same in the mroute table. If the source is sending for the
first time, the multicast control plane will then perform PIM registration or dense mode flooding based on the mode running
for the multicast group.
K Flag
The table describes the K flag.
Table 5. K Flag Description
Entry Flag
Description
K
Keepalive--Set by PIM to indicate that the entry has been processed and should be stored in the MFIB.
K Flag Sample Output
The K flag is set to indicate that the control plane (PIM/IGMP/TRANS) owns this entry. When the K flag is set the entry stays
in the MFIB until the control plane removes it.
If all flags on an entry (or interface) are removed, MFIB deletes the entry. Therefore, the K flag is used to ensure that
MFIB keeps the entry in the absence of any other entry flags (or interfaces with flags on the entry).
The following is sample output from the show ip mfib command. In this example, the output has been filtered to display only entries that have the K flag set.
Note
The K flag is displayed only when the verbose keyword is also specified.
RP# show ip mfib verbose | inc Flags: K
ET - Data Rate Exceeds Threshold, K - Keepalive Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kbits per second
(*,224.0.0.0/4) Flags: K
(*,224.0.1.40) Flags: C K
(*,232.0.0.0/8) Flags: K
(*,239.0.0.0/8) Flags: K
(*,239.1.1.1) Flags: IA K
IA Flag
The table describes the IA flag.
Table 6. IA Flag Description
Entry Flag
Description
IA
Inherit A Flag--(*, G) entries with the IA flag set indicate that the accept check be performed using its (*, G/mask) parent
entry. In other words, the accept check is used to inherit interfaces with the A flag set in the (*, G/m) parent entry.
Note
The IA flag is used for bidir-PIM entries.
IA Flag Sample Output
In the following output from the show ip mfib and show ip pim rp-mapping commands, the multicast group 239.195.1.1 is running bidir-PIM and there are two entries: (*, 239.195.1.1) and (*, 239.195.0.0/16).
The (*, 239.195.1.1) entry indicates that there is an interested receiver in the network. The parent entry, (*, 239.195.0.0/16),
indicates that there is a bidir-PIM group-to-RP mapping. The (*, 239.195.1.1) entry will be used for forwarding multicast
traffic for the multicast group 239.195.1.1. The (*, 239.195.1.1) entry will also have the IA flag set, indicating it will
inherit the following interfaces from its parent entry for performing accept checks: Serial interface 4/0, Serial interface
2/0, GigabitEthernet interface 0/0/0, and Null interface 0.
Note
The portions of output relevant to the IA flag are highlighted in bold.
Router# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0 Flags: F
Pkts: 0/0
GigabitEthernet0/0/0 Flags: F
Pkts: 0/0
Router# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0
Flags: A
F
Pkts: 0/0
Serial2/0
Flags: AGigabitEthernet0/0/0
Flags: A Null0
Flags: A
Router# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 00:49:10, expires: 00:02:19
A Flag
The table describes the A flag.
Table 7. A Flag Description
I/O Flag
Description
A
Accept--Indicates that multicast data can be accepted on this interface. For example, for PIM-SM and PIM-SSM, the A flag
would appear on the Reverse Path Forwarding (RPF) interface set in the mroute table.
Note
The A flag in the MFIB is cleared if MFIB forwarding has been disabled on the interface using the
no ip mfib forwarding input command.
A Flag Sample Output
Interfaces with the A flag set in the MFIB correspond to the incoming interfaces for their respective mroute entries, as shown
in the following output for the multicast group 239.1.1.1:
Note
The portions of sample output relevant to the A flag are highlighted in bold.
Router# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 366/0/28/0, Other: 0/0/0
Serial4/0 Flags: A
NS
GigabitEthernet0/0/0 Flags: F NS
Pkts: 366/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 107/10/28/2, Other: 1/1/0
Serial2/0 Flags: A
GigabitEthernet0/0/0 Flags: F NS
Pkts: 106/1
Router# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:00:40/stopped, RP 192.168.6.6, flags: SJC
Incoming interface: Serial4/0
, RPF nbr 192.168.67.6
Outgoing interface list:
GigabitEthernet0/0/0, Forward/Sparse, 00:00:40/00:02:59
(192.168.1.2, 239.1.1.1), 00:00:03/00:02:56, flags: JT
Incoming interface: Serial2/0
, RPF nbr 192.168.37.3
Outgoing interface list:
GigabitEthernet0/0/0, Forward/Sparse, 00:00:03/00:02:59
F Flag
The table describes the F flag.
Table 8. F Flag Description
I/O Flag
Description
F
Forward--Indicates that multicast data can be forwarded out this interface. For example, the interfaces that are in the outgoing
interface list in the mroute table will have this flag set.
Note
The F flag in the MFIB is cleared if the MFIB forwarding has been disabled on the interface using the
no ip mfib forwarding output command.
F Flag Sample Output
Interfaces with the F flag set in the MFIB correspond to interfaces in the outgoing interface list for their respective mroute
entries, as shown in the following output for the multicast group 239.1.1.1:
Note
The portions of sample output relevant to the F flag are highlighted in bold.
Router# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 366/0/28/0, Other: 0/0/0
Serial4/0 Flags: A NS
GigabitEthernet0/0 Flags: F
NS
Pkts: 366/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 107/10/28/2, Other: 1/1/0
Serial2/0 Flags: A
GigabitEthernet0/0/0 Flags: F
NS
Pkts: 106/1
Router# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:00:40/stopped, RP 192.168.6.6, flags: SJC
Incoming interface: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list: GigabitEthernet0/0
, Forward/Sparse, 00:00:40/00:02:59
(192.168.1.2, 239.1.1.1), 00:00:03/00:02:56, flags: JT
Incoming interface: Serial2/0, RPF nbr 192.168.37.3
Outgoing interface list:GigabitEthernet0/0/0
, Forward/Sparse, 00:00:03/00:02:59
NS Flag
The table describes the NS flag.
Table 9. NS Flag Description
I/O Flag
Description
NS
Negate Signal--Indicates the MFIB will notify the multicast control plane when traffic is received on the specified interface,
if the S flag is not set.
The NS flag is used for:
SPT switchover in PIM-SM--The NS flag is set on the (*, G) accept interface toward the RP to trigger SPT switchover.
Asserts--The NS flag is set on (*, G) and (S, G) forward interfaces to trigger PIM asserts.
Liveness checking for active sources in PIM-SM--The NS flag is set on the (S, G) accept interface toward the source to check
for active sources.
Proxy-registers that enable a PIM-DM domain to register within a PIM-SM domain--The NS flag is set on the (S, G) accept interface
where the
ip pim dense-mode proxy-register command is configured.
Note
For PIM-SSM, the accept interface entries will not have the NS flag set. PIM-SSM neither performs SPT-switchover nor liveness
checking.
Note
For PIM-SM, entries that have
ip pim spt-threshold infinity configured globally will not have the NS flag set on their accept interfaces because SPT switchover will be disabled.
IC Flag
The table describes the IC flag.
Table 10. IC Flag Description
I/O Flag
Description
IC
Internal Copy--Indicates that a copy of the packet will be processed by the control plane.
The IC flag applies to:
Static IGMP joins--Indicates that theip igmp join-group interface command is configured.
Auto-RP groups (224.0.1.39 and 224.0.1.40)--Indicates that the router is participating in Auto-RP.
Linkscope multicast groups (224.0.0.0/24)--Indicates that the router is listening to linkscope multicast groups, which include
PIM hellos, PIM joins and prunes, IGMPv2 /v3 reports, and Interior Gateway Protocol hello packets (Enhanced Interior Gateway
Routing Protocol [EIGRP], Open Shortest Path First [OSPF], and Routing Information Protocol version 2 [RIPv2]).
IC Flag Sample Output
Note
The configuration lines and portions of sample output relevant to the IC flag are highlighted in bold.
Static IGMP Join
The following example configures a static IGMP join for multicast group 239.1.1.1 under GigabitEthernet interface 0/0/0:
interface GigabitEthernet0/0/0
ip address 192.168.7.7 255.255.255.0
ip pim sparse-mode
ip igmp join-group 239.1.1.1
The following sample output from the show ip mfib command verifies that the IC flag is set for GigabitEthernet interface 0/0/0:
Router# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 366/0/28/0, Other: 0/0/0
Serial4/0 Flags: A NS
GigabitEthernet0/0/0
Flags: F IC
NS
Pkts: 366/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 3978/10/28/2, Other: 1/1/0
Serial2/0 Flags: A
GigabitEthernet0/0/0
Flags: F IC
NS
Pkts: 3977/1
Note
The ip igmp static-group command will not set the IC flag.
Auto-RP Groups 224.0.1.39 and 224.0.1.40
The following output from the show ip igmp group and show ip mfib command confirms that this router is both an RP and Mapping Agent and has the IC flag set to process switch Auto-RP multicast
packets.
Note
All routers, including the RP, will join the multicast group 224.0.1.40. In addition to the multicast group 224.0.1.40, Mapping
Agents will also join 224.0.1.39.
Router# show ip igmp group
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
224.0.1.39 Serial2/0
02:57:51 stopped 192.168.26.6
224.0.1.39 Serial1/0
02:57:51 stopped 192.168.67.6
224.0.1.39 GigabitEthernet0/0/0
02:57:51 00:02:11 192.168.16.6
224.0.1.39 Loopback0
02:57:51 00:02:07 192.168.6.6
224.0.1.40 Loopback0
02:57:51 00:02:11 192.168.6.6
239.1.1.1 GigabitEthernet0/0/0 02:58:51 00:02:13 192.168.16.6
224.1.1.1 GigabitEthernet0/0/0 02:58:51 00:02:13 192.168.16.6
Router# show ip mfib 224.0.1.39
(*,224.0.1.39) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: F IC NS
Pkts: 0/0
Serial2/0 Flags: F IC NS
Pkts: 0/0
Serial1/0 Flags: F IC NS
Pkts: 0/0
GigabitEthernet0/0/0 Flags: F IC NS
Pkts: 0/0
(192.168.6.6,224.0.1.39) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: A IC
Serial2/0 Flags: F IC NS
Pkts: 0/0
Serial1/0 Flags: F IC NS
Pkts: 0/0
GigabitEthernet0/0/0 Flags: F IC NS
Pkts: 0/0
Router# show ip mfib 224.0.1.40
(*,224.0.1.40) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: F IC NS
Pkts: 0/0
Serial2/0 Flags: F NS
Pkts: 0/0
Serial1/0 Flags: F NS
Pkts: 0/0
(192.168.6.6,224.0.1.40) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: A IC
Serial2/0 Flags: F NS
Pkts: 0/0
Serial1/0 Flags: F NS
Pkts: 0/0
Linkscope Multicast Groups 224.0.0.0/24
The following output from the show ip mfib linkscope command confirms that the IC flag is set to process multicast control packets:
Router# show ip mfib linkscope
.
.
.
(*,224.0.0.1) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: IC
Serial4/0 Flags: IC
Serial3/0 Flags: IC
Serial2/0 Flags: IC
GigabitEthernet1/0/0 Flags: IC
GigabitEthernet0/0/0 Flags: IC
(*,224.0.0.2) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: IC
Serial4/0 Flags: IC
Serial3/0 Flags: IC
Serial2/0 Flags: IC
GigabitEthernet1/0/0 Flags: IC
GigabitEthernet0/0/0 Flags: IC
(*,224.0.0.13) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: IC
Serial4/0 Flags: IC
Serial3/0 Flags: IC
Serial2/0 Flags: IC
GigabitEthernet1/0/0 Flags: IC
GigabitEthernet0/0/0 Flags: IC
(*,224.0.0.22) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback0 Flags: IC
Serial4/0 Flags: IC
Serial3/0 Flags: IC
Serial2/0 Flags: IC
GigabitEthernet1/0/0 Flags: IC
GigabitEthernet0/0/0 Flags: IC
PIM Tunnel Interfaces
PIM tunnel interfaces are used by MFIB for the PIM-SM registration process. Two types of PIM tunnel interfaces are used by
the MFIB:
A PIM encapsulation tunnel (PIM Encap Tunnel)
A PIM decapsulation tunnel (PIM Decap Tunnel)
The PIM Encap Tunnel is dynamically created whenever a group-to-RP mapping is learned (via Auto-RP, BSR, or static RP configuration).
The PIM Encap Tunnel is used to encapsulate multicast packets sent by first-hop DRs that have directly connected sources.
Similar to the PIM Encap Tunnel, the PIM Decap Tunnel interface is dynamically created--with the exception that it is created
on the RP only whenever a group-to-RP mapping is learned. The PIM Decap Tunnel interface is used by the RP to decapsulate
PIM registers.
Note
PIM tunnels will not appear in the running configuration.
The following syslog message will appear when a PIM tunnel interface is created:
* %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel<interface_number>, changed state to up
How to Verify IPv4 Multicast Forwarding Using the MFIB
Verifying IPv4 Multicast Forwarding Using the MFIB for PIM-SM PIM-SSM and Bidir-PIM
Perform this optional task to verify multicast forwarding using the MFIB in PIM-SM, PIM-SSM, and bidir-PIM networks.
When you verify IPv4 multicast forwarding using the MFIB in PIM network environments, a useful approach is to begin the verification
process on the last-hop DR, and then continue the verification process on the routers along the SPT for PIM-SM or PIM-SSM
(or on the shared tree for bidir-PIM) until the first-hop DR has been reached. The goal of the verification is to ensure that
IP multicast traffic is being forwarded properly through an IP multicast network.
Before you begin
The tasks in this module assume that IP multicast has been enabled and that PIM-SM, PIM-SSM, or bidir-PIM have been configured.
Note
You must be running a Cisco software image that supports the IPv4 MFIB infrastructure.
>
SUMMARY STEPS
enable
show ip mroute
show ip mrib route
show ip mfib
show ip pim rp mapping
show ip igmp groups
DETAILED STEPS
Step 1
enable
Enables privileged EXEC mode. Enter your password if prompted.
Router> enable
Step 2
show ip mroute
Displays the contents of the mroute table.
Router# show ip mroute
Step 3
show ip mrib route
Displays the MRIB table.
Router# show ip mrib route
Step 4
show ip mfib
Displays the forwarding entries and interfaces in the MFIB.
Router# show ip mfib
Step 5
show ip pim rp mapping
Displays all group-to-RP mappings of which the router is aware (either configured or learned from Auto-RP or BSR). Use this
command to confirm which router is acting as the RP.
Note
The show ip pim rp mapping command does not apply to routers in a PIM-SSM network because PIM-SSM does not use RPs.
Sample Output from an RP
The following is sample output from the show ip pim rp mapping command. The output confirms that the router in this example is the RP.
Example:
RP# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 01:04:03, expires: 00:02:53
Sample Output from a Non-RP
The following is sample output from the show ip pim rp mapping command. The output confirms that this router is not the RP.
Example:
Non-RP# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 00:40:55, expires: 00:02:45
Step 6
show ip igmp groups
Displays the multicast groups with receivers that are directly connected to the router and that were learned through IGMP.
Use this command to confirm that the IGMP cache is being properly populated on the last-hop DR for the groups that receivers
on the LAN have joined.
Router# show ip igmp groups
Verifying PIM Tunnel Interfaces for PIM-SM
Perform this optional task verify to verify the PIM tunnel interfaces that are used by the MFIB for the PIM-SM registration
process. This task can be performed if you suspect that there may be problems related to PIM-SM registration.
SUMMARY STEPS
enable
show ip pim rp mapping
show ip pim tunnel
show ip mfib
DETAILED STEPS
Step 1
enable
Enables privileged EXEC mode. Enter your password if prompted.
Router> enable
Step 2
show ip pim rp mapping
Displays all group-to-RP mappings of which the router is aware (either configured or learned from Auto-RP or BSR). Use this
command to confirm which router is acting as the RP.
Sample Output from an RP
The following is sample output from the show ip pim rp mapping command. The output confirms that the router in this example is the RP.
Example:
RP# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 01:04:03, expires: 00:02:53
Sample Output from a Non-RP
The following is sample output from the show ip pim rp mapping command. The output confirms that this router is not the RP.
Example:
Non-RP# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 00:40:55, expires: 00:02:45
Step 3
show ip pim tunnel
Displays the PIM tunnel interfaces used by the MFIB for the PIM-SM registration process.
Sample Output from an RP (show ip pim tunnel)
The following is output from theshow ip pim tunnel command. The output is used to verify the PIM Encap and Decap Tunnel on the RP.
Example:
RP# show ip pim tunnel
Tunnel0
Type : PIM Encap
RP : 192.168.6.6*
Source: 192.168.6.6
Tunnel1
Type : PIM Decap
RP : 192.168.6.6*
Source: -
Note
The asterisk (*) indicates that the router is the RP. The RP will always have a PIM Encap and Decap Tunnel interface.
Sample Output from a Non-RP (show ip pim tunnel)
The following is output from the show ip pim tunnel command. The output is used to confirm that a PIM Encap Tunnel has been created on a non-RP router.
Example:
Non-RP# show ip pim tunnel
Tunnel0
Type : PIM Encap
RP : 192.168.6.6
Source: 192.168.67.7
Step 4
show ip mfib
Displays the forwarding entries and interfaces in the MFIB.
or
show ip mrib route
Displays the MRIB table.
Use either theshow ip mfib command or the show ip mrib route command to verify that the entries registering for PIM-SM have the F flag set for the PIM Encap Tunnel.
Configuration Examples for Verifying IPv4 Multicast Forwarding Using the MFIB
Examples Verifying IPv4 Multicast Forwarding Using the MFIB for PIM-SM
This section contains the following examples for verifying multicast forwarding using the MFIB for PIM-SM networks:
Note
The examples in this section were created in a test environment to provide a conceptual view of the multicast environment.
The IP addresses, interfaces, and other values are shown as examples only. They do not show real-world deployment values.
PIM-SM Example Active Sources and Interested Receivers - SPT Switchover
The following example shows how to verify multicast forwarding using the MFIB for PIM-SM in a network environment where there
are active sources with interested receivers. This verification example is based on the topology shown in the figure.
Figure 1. PIM-SM Example Topology: Active Sources and Interested Receivers (SPT Switchover)
In this verification example, the following conditions apply:
All routers have the SPT switchover set to the default (ip pim spt-threshold 0 ).
Because the SPT threshold is set to 0, all last-hop DRs with interested receivers will perform an SPT switchover when multicast
traffic is received on the shared tree.
During the PIM-SM registration process between the first-hop DR and the RP, a PIM tunnel is used. First-hop DRs will have
a PIM Encap Tunnel and the RP will have both a PIM Encap and Decap Tunnel. After the PIM-SM registration process completes,
PIM tunnels will not be used for multicast forwarding. For more information, see the
Verifying PIM Tunnel Interfaces for PIM-SM section.
R1 (First-Hop DR)
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R1# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:53:08/stopped, RP 192.168.6.6, flags: SPF
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list: Null
(192.168.1.2, 239.1.1.1), 00:53:08/00:03:12, flags: FT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:38:25/00:03:07
R1# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.123.2 Flags: C
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet0/0 Flags: A
Ethernet1/0 Flags: F NS
R1# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 23058/0/23058
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 23059/10/28/2, Other: 8826/0/8826
Ethernet0/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 23058/0
R2 (Router Along the SPT)
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R2# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:39:05/00:02:53, RP 192.168.6.6, flags: S
Incoming interface: Serial2/0, RPF nbr 192.168.26.6
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:39:05/00:02:53
(192.168.16.1, 239.1.1.1), 00:03:31/00:02:54, flags: T
Incoming interface: Serial2/0, RPF nbr 192.168.26.6
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:03:31/00:02:56
(192.168.1.2, 239.1.1.1), 00:39:05/00:02:42, flags: PT
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.1
Outgoing interface list: Null
R2# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.26.6 Flags: C
Ethernet1/0 Flags: F NS
Serial2/0 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.123.1 Flags:
Ethernet1/0 Flags: A
(192.168.16.1,239.1.1.1) RPF nbr: 192.168.26.6 Flags:
Serial2/0 Flags: A
Ethernet1/0 Flags: F NS
R2# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 21343/0/28/0, Other: 0/0/0
Serial2/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 21343/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 21643/0/28/0, Other: 1812/1/1811
Ethernet1/0 Flags: A
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 2112/10/28/2, Other: 0/0/0
Serial2/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 2112/0
R3 (Router Along the SPT)
R3# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R3# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:40:32/00:03:19, RP 192.168.6.6, flags: S
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list:
Serial3/0, Forward/Sparse, 00:40:32/00:03:19
(192.168.16.1, 239.1.1.1), 00:04:58/00:02:29, flags: T
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list:
Serial3/0, Forward/Sparse, 00:04:58/00:03:26
(192.168.1.2, 239.1.1.1), 00:04:58/00:02:26, flags: T
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.1
Outgoing interface list:
Serial2/0, Forward/Sparse, 00:04:28/00:02:57
Serial3/0, Forward/Sparse, 00:04:58/00:03:27
R3# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.123.2 Flags: C
Serial3/0 Flags: F NS
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.123.1 Flags:
Ethernet1/0 Flags: A
Serial2/0 Flags: F NS
Serial3/0 Flags: F NS
(192.168.16.1,239.1.1.1) RPF nbr: 192.168.123.2 Flags:
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
R3# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 42686/0/28/0, Other: 0/0/0
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
Pkts: 42686/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 2984/10/28/2, Other: 0/0/0
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
Pkts: 2984/0
Serial2/0 Flags: F NS
Pkts: 2684/0
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 2984/10/28/2, Other: 0/0/0
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
Pkts: 2984/0
R4 (Last-Hop DR for Receiver B)
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R4# show ip igmp groups 239.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.1.1.1 Ethernet0/0 00:06:39 00:02:56 192.168.4.1
R4# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:42:12/stopped, RP 192.168.6.6, flags: SJC
Incoming interface: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:42:12/00:02:02
(192.168.16.1, 239.1.1.1), 00:06:37/00:02:16, flags: JT
Incoming interface: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:06:37/00:02:02
(192.168.1.2, 239.1.1.1), 00:06:37/00:02:19, flags: JT
Incoming interface: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:06:37/00:02:02
R4# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.34.3 Flags: C
Serial1/0 Flags: A NS
Ethernet0/0 Flags: F NS
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.34.3 Flags:
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
(192.168.16.1,239.1.1.1) RPF nbr: 192.168.34.3 Flags:
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
R4# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 42684/0/28/0, Other: 0/0/0
Serial1/0 Flags: A NS
Ethernet0/0 Flags: F NS
Pkts: 42684/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 3980/10/28/2, Other: 0/0/0
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 3979/1
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 3980/10/28/2, Other: 0/0/0
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 3979/1
R6 (RP and First-Hop DR for Source B)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:10:53, expires: 00:02:06
R6# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:58:12/00:03:25, RP 192.168.6.6, flags: SF
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 00:43:25/00:03:22
Serial2/0, Forward/Sparse, 00:43:29/00:03:25
(192.168.1.2, 239.1.1.1), 00:58:12/00:02:47, flags: PT
Incoming interface: Serial2/0, RPF nbr 192.168.26.2
Outgoing interface list: Null
(192.168.16.1, 239.1.1.1), 00:58:12/00:03:17, flags: FT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 00:43:25/00:03:22
Serial2/0, Forward/Sparse, 00:43:29/00:03:27
R6# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 0.0.0.0 Flags: C
Serial1/0 Flags: F NS
Serial2/0 Flags: F NS
Tunnel1 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.26.2 Flags:
Serial2/0 Flags: A NS
(192.168.16.1,239.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet0/0 Flags: A
Serial1/0 Flags: F NS
Serial2/0 Flags: F NS
R6# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Tunnel1 Flags: A
Serial2/0 Flags: F NS
Pkts: 0/0
Serial1/0 Flags: F NS
Pkts: 0/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 21604/0/28/0, Other: 39/1/38
Serial2/0 Flags: A NS
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 26099/10/28/2, Other: 8827/0/8827
Ethernet0/0 Flags: A
Serial2/0 Flags: F NS
Pkts: 26098/0
Serial1/0 Flags: F NS
Pkts: 26058/0
R7 (Last-Hop DR for Receiver A)
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R7# show ip igmp groups 239.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.1.1.1 Ethernet0/0 00:08:47 00:02:56 192.168.7.1
R7# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:44:45/stopped, RP 192.168.6.6, flags: SJC
Incoming interface: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:44:45/00:02:47
(192.168.1.2, 239.1.1.1), 00:08:45/00:02:13, flags: JT
Incoming interface: Serial2/0, RPF nbr 192.168.37.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:08:45/00:02:47
(192.168.16.1, 239.1.1.1), 00:08:45/00:02:10, flags: JT
Incoming interface: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:08:45/00:02:47
R7# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.67.6 Flags: C
Serial4/0 Flags: A NS
Ethernet0/0 Flags: F NS
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.37.3 Flags:
Serial2/0 Flags: A
Ethernet0/0 Flags: F NS
(192.168.16.1,239.1.1.1) RPF nbr: 192.168.67.6 Flags:
Serial4/0 Flags: A
Ethernet0/0 Flags: F NS
R7# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 43204/0/28/0, Other: 0/0/0
Serial4/0 Flags: A NS
Ethernet0/0 Flags: F NS
Pkts: 43204/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 5255/10/28/2, Other: 1/1/0
Serial2/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 5254/1
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 5255/10/28/2, Other: 0/0/0
Serial4/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 5254/1
PIM-SM Example Active Sources and Interested Receivers - SPT Threshold Set to Infinity
The following example shows how to verify multicast forwarding using the MFIB for PIM-SM in a network environment where there
are active sources with interested receivers. This verification example is based on the topology shown in the figure.
Figure 2. PIM-SM Example Topology: Active Sources and Interested Receivers (SPT Threshold Set to Infinity)
For this verification example, the following conditions apply:
Last-hop DRs R4 and R7 have the SPT threshold set to infinity (configured with the
ip pim spt-threshold infinity command).
Note
When the SPT threshold is set to infinity, multicast traffic is configured to stay on the shared tree. Last-hop DRs will
not perform an SPT switchover.
During the PIM-SM registration process between the first-hop DR and the RP, a PIM tunnel is used. First-hop DRs will have
a PIM Encap Tunnel and the RP will have both a PIM Encap and Decap Tunnel. After the PIM-SM registration process completes,
PIM tunnels will not be used for multicast forwarding. For more information, see the
Verifying PIM Tunnel Interfaces for PIM-SM section.
R1 (First-Hop DR for Source A)
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R1# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:37:29/stopped, RP 192.168.6.6, flags: SPF
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list: Null
(192.168.1.2, 239.1.1.1), 00:37:29/00:02:53, flags: FT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:22:46/00:03:19
R1# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.123.2 Flags: C
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet0/0 Flags: A
Ethernet1/0 Flags: F NS
R1# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 13688/0/13688
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 13689/10/28/2, Other: 8826/0/8826
Ethernet0/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 13688/0
R2 (Router Along SPT for Source A and Shared Tree for Source B)
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R2# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:23:28/00:02:44, RP 192.168.6.6, flags: S
Incoming interface: Serial2/0, RPF nbr 192.168.26.6
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:23:28/00:02:44
(192.168.1.2, 239.1.1.1), 00:23:28/00:02:54, flags: T
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.1
Outgoing interface list:
Serial2/0, Forward/Sparse, 00:23:28/00:02:40
R2# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.26.6 Flags: C
Ethernet1/0 Flags: F NS
Serial2/0 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.123.1 Flags:
Ethernet1/0 Flags: A
Serial2/0 Flags: F NS
R2# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 14084/10/28/2, Other: 0/0/0
Serial2/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 14084/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 14083/10/28/2, Other: 1/1/0
Ethernet1/0 Flags: A
Serial2/0 Flags: F NS
Pkts: 14083/0
R3 (Router Along the Shared Tree)
R3# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R3# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:23:57/00:03:10, RP 192.168.6.6, flags: S
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list:
Serial3/0, Forward/Sparse, 00:23:57/00:03:10
R3# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.123.2 Flags: C
Serial3/0 Flags: F NS
Ethernet1/0 Flags: A
R3# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 28742/20/28/4, Other: 0/0/0
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
Pkts: 28742/0
R4 (Last-Hop DR for Receiver B)
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R4# show ip igmp groups 239.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.1.1.1 Ethernet0/0 00:24:37 00:02:56 192.168.4.1
R4# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:24:35/00:02:35, RP 192.168.6.6, flags: SC
Incoming interface: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:24:35/00:02:35
R4# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.34.3 Flags: C
Ethernet0/0 Flags: F NS
Serial1/0 Flags: A
R4# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 29517/20/28/4, Other: 0/0/0
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 29517/0
R6 (RP and First-Hop DR for Source B)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:10:53, expires: 00:02:06
R6# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:39:44/00:03:09, RP 192.168.6.6, flags: SF
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 00:24:57/00:03:09
Serial2/0, Forward/Sparse, 00:25:01/00:03:09
(192.168.1.2, 239.1.1.1), 00:39:44/00:03:18, flags: T
Incoming interface: Serial2/0, RPF nbr 192.168.26.2
Outgoing interface list:
Serial1/0, Forward/Sparse, 00:24:57/00:03:09
(192.168.16.1, 239.1.1.1), 00:39:44/00:02:35, flags: FT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 00:24:57/00:03:09
Serial2/0, Forward/Sparse, 00:25:01/00:03:09
R6# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 0.0.0.0 Flags: C
Serial1/0 Flags: F NS
Serial2/0 Flags: F NS
Tunnel1 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.26.2 Flags:
Serial2/0 Flags: A
Serial1/0 Flags: F NS
(192.168.16.1,239.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet0/0 Flags: A
Serial1/0 Flags: F NS
Serial2/0 Flags: F NS
R6# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Tunnel1 Flags: A
Serial2/0 Flags: F NS
Pkts: 0/0
Serial1/0 Flags: F NS
Pkts: 0/0
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 14978/10/28/2, Other: 39/1/38
Serial2/0 Flags: A
Serial1/0 Flags: F NS
Pkts: 14978/0
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 15019/10/28/2, Other: 8827/0/8827
Ethernet0/0 Flags: A
Serial2/0 Flags: F NS
Pkts: 15018/0
Serial1/0 Flags: F NS
Pkts: 14978/0
R6# show ip pim tunnel
Tunnel0
Type : PIM Encap
RP : 192.168.6.6*
Source: 192.168.6.6
Tunnel1*
Type : PIM Decap
RP : 192.168.6.6*
Source: -
R7 (Last-Hop DR for Receiver A)
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R7# show ip igmp groups 239.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.1.1.1 Ethernet0/0 00:25:39 00:02:56 192.168.7.1
R7# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:25:37/00:02:58, RP 192.168.6.6, flags: SC
Incoming interface: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:25:37/00:02:58
R7# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.67.6 Flags: C
Ethernet0/0 Flags: F NS
Serial4/0 Flags: A
R7# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 30756/20/28/4, Other: 0/0/0
Serial4/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 30756/0
PIM-SM Example Source Traffic Only with No Receivers
The following example shows how to verify multicast forwarding using the MFIB for PIM-SM in a network environment where sources
are sending traffic without interested receivers. This verification example is based on the topology shown in the figure.
Figure 3. PIM-SM Example Topology: Source Traffic Only with No Receivers
In this verification example, the following conditions apply:
Source A and Source B are sending traffic for multicast group 239.1.1.1 to first-hop DRs R1 and R6, respectively.
When R1 and R6 receive the source traffic, they will then check their group-to-RP mapping cache for multicast group 239.1.1.1
to determine the RP. In this case, R6 is the RP.
After determining the RP, R1 and R6 will then create state and send PIM registers for (Source A, 239.1.1.1) and (Source B,
239.1.1.1) toward the RP.
Because there are no interested receivers, the RP will send a register stop to R1 and R6 (itself).
R1 and R6 are the only routers that will have (S, G) state for 239.1.1.1.
Routers that are not the RP or directly connected to an active source will not create state for (*, 239.1.1.1).
R1 (First-Hop DR for Source A)
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R1# show ip mroute 239.1.1.1
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.1), 00:02:06/stopped, RP 192.168.6.6, flags: SPF
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list: Null
(192.168.1.2, 239.1.1.1), 00:02:06/00:02:53, flags: PFT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list: Null
R1# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.123.2 Flags: C
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet0/0 Flags: A
R1# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Ethernet1/0 Flags: A
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 1/0/28/0, Other: 1267/0/1267
Ethernet0/0 Flags: A
R6 (RP and First-Hop DR for Source B)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:10:53, expires: 00:02:06
R6# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:02:48/stopped, RP 192.168.6.6, flags: SPF
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list: Null
(192.168.1.2, 239.1.1.1), 00:02:42/00:02:17, flags: P
Incoming interface: Serial2/0, RPF nbr 192.168.26.2
Outgoing interface list: Null
(192.168.16.1, 239.1.1.1), 00:02:48/00:02:11, flags: PFT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list: Null
R6# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 0.0.0.0 Flags: C
Tunnel1 Flags: A
(192.168.1.2,239.1.1.1) RPF nbr: 192.168.26.2 Flags:
Serial2/0 Flags: NS
Tunnel1 Flags: A
(192.168.16.1,239.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet0/0 Flags: A
R6# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Tunnel1 Flags: A
(192.168.1.2,239.1.1.1) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Tunnel1 Flags: A
Serial2/0 Flags: NS
(192.168.16.1,239.1.1.1) Flags:
SW Forwarding: 1/0/28/0, Other: 1688/0/1688
Ethernet0/0 Flags: A
R6# show ip pim tunnel
Tunnel0
Type : PIM Encap
RP : 192.168.6.6*
Source: 192.168.6.6
Tunnel1*
Type : PIM Decap
RP : 192.168.6.6*
Source: -
In this scenario, R2, R3, R4, and R7 have no interested receivers; therefore, they are not on the multicast forwarding path
and will not have multicast state. The output for the
show ip mroute ,
show ip mrib route , and
show ip mfib route commands would appear only on R2, R3, R4, and R7, as in this example (taken from R2):
R2 (Router Not Along the Multicast Forwarding Path)
R2# show ip mroute 239.1.1.1
Group 239.1.1.1 not found
R2# show ip mrib route 239.1.1.1
No matching routes in MRIB route-DB
R2# show ip mfib 239.1.1.1
Group 239.1.1.1 not found
Note
The output for the
show ip mroute ,show ip mrib route , and
show ip mfib commands would be the same for R2, R3, R4, and R7 for this scenario.
PIM-SM Example Interested Receivers with No Active Sources
The following example shows how to verify multicast forwarding using the MFIB for PIM-SM in a network environment where there
are interested receivers with no active sources. This verification example is based on the topology shown in the figure.
Figure 4. PIM-SM Example Topology: Interested Receivers with No Active Sources
For this verification example, the following conditions apply:
Last-hop DRs R4 and R7 also have the SPT threshold set to infinity (configured with the
ip pim spt-threshold infinity command).
Note
When the SPT threshold is set to infinity, multicast traffic is configured to stay on the shared tree. Last-hop DRs will
not perform an SPT switchover.
Receiver A and Receiver B are sending IGMP joins to R7 and R4, respectively, for multicast group 239.1.1.1.
When R4 and R7 receive the IGMP joins, they will then check their group-to-RP mapping cache for multicast group 239.1.1.1
to determine the RP.
After determining the RP, R4 and R7 will then create state and send PIM joins for (*, 239.1.1.1) toward the RP.
Note
The unicast routing table is used to build the shared tree entry for (*, 239.1.1.1). Shared tree entries are always rooted
at the RP. In this scenario, the shared tree from R4 to R6 is through R3 and R2 because R3’s best unicast route (determined
by the underlying IGP) is R2. The shared tree for R7 is directly upstream to R6.
Routers that are not along the shared tree will not create state for (*, 239.1.1.1).
R4 (Last-Hop DR)
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R4# show ip igmp groups 239.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.1.1.1 Ethernet0/0 00:03:07 00:02:56 192.168.4.1
R4# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:03:05/00:02:47, RP 192.168.6.6, flags: SJC
Incoming interface: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:03:05/00:02:47
R4# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.34.3 Flags: C
Ethernet0/0 Flags: F NS
Serial1/0 Flags: A NS
R4# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial1/0 Flags: A NS
Ethernet0/0 Flags: F NS
Pkts: 0/0
R3 (Router Along the Shared Tree)
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R3# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:03:40/00:02:47, RP 192.168.6.6, flags: S
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list:
Serial3/0, Forward/Sparse, 00:03:40/00:02:47
R3# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.123.2 Flags: C
Serial3/0 Flags: F NS
Ethernet1/0 Flags: A
R3# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
Pkts: 0/0
R2 (Router Along the Shared Tree)
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R2# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:04:05/00:03:20, RP 192.168.6.6, flags: S
Incoming interface: Serial2/0, RPF nbr 192.168.26.6
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:04:05/00:03:20
R2# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.26.6 Flags: C
Ethernet1/0 Flags: F NS
Serial2/0 Flags: A
R2# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial2/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 0/0
R7 (Last-Hop DR)
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:09:53, expires: 00:02:14
R7# show ip igmp groups 239.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.1.1.1 Ethernet0/0 00:04:33 00:02:56 192.168.7.1
R7# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:04:31/00:02:36, RP 192.168.6.6, flags: SJC
Incoming interface: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:04:31/00:02:36
R7# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 192.168.67.6 Flags: C
Ethernet0/0 Flags: F NS
Serial4/0 Flags: A NS
R7# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0 Flags: A NS
Ethernet0/0 Flags: F NS
Pkts: 0/0
R6 (RP)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 224.0.0.0/4
RP 192.168.6.6 (?), v2v1
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 03:10:53, expires: 00:02:06
R6# show ip mroute 239.1.1.1
(*, 239.1.1.1), 00:05:01/00:03:27, RP 192.168.6.6, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 00:04:57/00:03:27
Serial2/0, Forward/Sparse, 00:05:01/00:03:23
R6# show ip mrib route 239.1.1.1
(*,239.1.1.1) RPF nbr: 0.0.0.0 Flags: C
Serial1/0 Flags: F NS
Serial2/0 Flags: F NS
Tunnel1 Flags: A
R6# show ip mfib 239.1.1.1
(*,239.1.1.1) Flags: C
SW Forwarding: 0/0/0/0, Other: 0/0/0
Tunnel1 Flags: A
Serial2/0 Flags: F NS
Pkts: 0/0
Serial1/0 Flags: F NS
Pkts: 0/0
R6# show ip pim tunnel
Tunnel0
Type : PIM Encap
RP : 192.168.6.6*
Source: 192.168.6.6
Tunnel1*
Type : PIM Decap
RP : 192.168.6.6*
Source: -
R1 (Router Not Along the Multicast Forwarding Path)
R1# show ip mroute 239.1.1.1
Group 239.1.1.1 not found
R1# show ip mrib route 239.1.1.1
No matching routes in MRIB route-DB
R1# show ip mfib 239.1.1.1
Group 239.1.1.1 not found
Note
R1 does not have any state for 239.1.1.1 because it does not have an interested receiver, is not along the shared tree path,
and does not have a directly connected source.
Examples Verifying IPv4 Multicast Forwarding Using the MFIB for PIM-SSM
Note
The examples in this section were created in a test environment to provide a conceptual view of the multicast environment.
The IP addresses, interfaces, and other values are shown as examples only. They do not show real-world deployment values.
PIM-SSM Example Interested Receivers With or Without Active Sources
The following example shows how to verify multicast forwarding using the MFIB for PIM-SSM in a network environment where
there are interested receivers with or without active sources. This verification example is based on the topology shown in
the figure.
Figure 5. PIM-SSM Example Topology: Interested Receivers With or Without Active Sources
For this verification example, the following conditions apply:
All routers in the network have been configured to run PIM-SSM and have theip pim ssm default command configured globally.
Source A is sending multicast packets to SSM group 232.1.1.1.
Receiver A and Receiver B are interested in receiving multicast from Source A, (192.168.1.2, 232.1.1.1).
Receiver A and Receiver B are using IGMPv3.
R1 (First-Hop DR for Source A)
R1# show ip mroute 232.1.1.1
(192.168.1.2, 232.1.1.1), 00:07:18/00:03:02, flags: sT
Incoming interface: Ethernet0/0, RPF nbr 0.0.0.0
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 00:07:18/00:03:02
R1# show ip mrib route 232.1.1.1
(192.168.1.2,232.1.1.1) RPF nbr: 0.0.0.0 Flags:
Ethernet1/0 Flags: F NS
Ethernet0/0 Flags: A
R1# show ip mfib 232.1.1.1
(192.168.1.2,232.1.1.1) Flags:
SW Forwarding: 3039/10/28/2, Other: 0/0/0
Ethernet0/0 Flags: A
Ethernet1/0 Flags: F NS
Pkts: 3039/0
R3 (Router Along the SPT)
R3# show ip mroute 232.1.1.1
(192.168.1.2, 232.1.1.1), 00:08:00/00:03:13, flags: sT
Incoming interface: Ethernet1/0, RPF nbr 192.168.123.1
Outgoing interface list:
Serial3/0, Forward/Sparse, 00:08:00/00:03:13
Serial2/0, Forward/Sparse, 00:08:00/00:02:59
R3# show ip mrib route 232.1.1.1
(192.168.1.2,232.1.1.1) RPF nbr: 192.168.123.1 Flags:
Serial3/0 Flags: F NS
Serial2/0 Flags: F NS
Ethernet1/0 Flags: A
R3# show ip mfib 232.1.1.1
(192.168.1.2,232.1.1.1) Flags:
SW Forwarding: 3514/10/28/2, Other: 0/0/0
Ethernet1/0 Flags: A
Serial3/0 Flags: F NS
Pkts: 3514/0
Serial2/0 Flags: F NS
Pkts: 3514/0
R4 (Last-Hop DR for Receiver B)
R4# show ip igmp groups 232.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
232.1.1.1 Ethernet0/0 00:12:46 stopped 192.168.4.1
R4# show ip mroute 232.1.1.1
(192.168.1.2, 232.1.1.1), 00:08:42/stopped, flags: sTI
Incoming interface: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:08:42/00:00:17
R4# show ip mrib route 232.1.1.1
(192.168.1.2,232.1.1.1) RPF nbr: 192.168.34.3 Flags:
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
R4# show ip mfib 232.1.1.1
(192.168.1.2,232.1.1.1) Flags:
SW Forwarding: 3786/10/28/2, Other: 0/0/0
Serial1/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 3786/0
R7 (Last-Hop DR for Receiver A)
R7# show ip igmp groups 232.1.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
232.1.1.1 Ethernet0/0 00:12:24 stopped 192.168.7.1
R7# show ip mroute 232.1.1.1
(192.168.1.2, 232.1.1.1), 00:09:37/stopped, flags: sTI
Incoming interface: Serial2/0, RPF nbr 192.168.37.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 00:09:37/00:02:22
R7# show ip mrib route 232.1.1.1
(192.168.1.2,232.1.1.1) RPF nbr: 192.168.37.3 Flags:
Serial2/0 Flags: A
Ethernet0/0 Flags: F NS
R7# show ip mfib 232.1.1.1
(192.168.1.2,232.1.1.1) Flags:
SW Forwarding: 4182/10/28/2, Other: 0/0/0
Serial2/0 Flags: A
Ethernet0/0 Flags: F NS
Pkts: 4182/0
PIM-SSM Example Source Traffic Only with No Active Receivers
The following example shows how to verify multicast forwarding using the MFIB for PIM-SSM in a network environment where
there is an active source with no interested receivers. This verification example is based on the topology shown in the figure.
Figure 6. PIM-SSM Example Topology: Source Traffic Only with No Active Receivers
For this verification example, the following conditions apply:
All routers in the network have been configured to run PIM-SSM and have theip pim ssm default command configured globally.
Source A is sending multicast packets to SSM group 232.1.1.1.
Source B is not actively sending.
There are no interested receivers in the network.
Routers that support the MFIB will not create state for SSM multicast groups until a join has been requested by an interested
receiver, which means that any routers with active sources sending to an SSM group will not have multicast state. Because
there are no interested receivers in this network, none of the routers will create state for (192.168.1.2, 232.1.1.1).
The following is output from the
show ip mroute ,
show ip mrib route , and
show ip mfib commands taken from R1:
R1
R1# show ip mroute 239.1.1.1
Group 239.1.1.1 not found
R1# show ip mrib route 239.1.1.1
No matching routes in MRIB route-DB
R1# show ip mfib 239.1.1.1
Group 239.1.1.1 not found
Note
Because there are no interested receivers in this network, the output from the
show ip mroute ,
show ip mrib route , and
show ip mfib commands would be the same on R3, R4, and R7 in this example scenario.
PIM-SSM Example Unwanted Sources in the SSM Network
The following example shows how to verify multicast forwarding using the MFIB for PIM-SSM in a network environment where
there is an unwanted source. This verification example is based on the topology shown in the figure.
Figure 7. PIM-SSM Example Topology: Unwanted Sources in the SSM Network
For this verification example, the following conditions apply:
All routers in the network have been configured to run PIM-SSM and have theip pim ssm default command configured globally.
Receiver A and Receiver B are only interested in receiving multicast from Source A, (192.168.1.2, 232.1.1.1).
Unwanted source, Source B, is sending traffic to 232.1.1.1.
Note
Even though Source B is directly connected to R3, R3 will not create state for 232.1.1.1. Multicast traffic from Source B
sending to SSM group 232.1.1.1, thus, will be immediately dropped by the router.
R3 (First-Hop DR for Unwanted Source B)
R3# show ip mroute 232.1.1.1 192.168.3.1
R3# show ip mrib route 232.1.1.1 192.168.3.1
No matching routes in MRIB route-DB
R3# show ip mfib 232.1.1.1 192.168.3.1
(192.168.3.1,232.1.1.1) entry not found
Note
Likewise, R1, R4, and R7 will also have no multicast state for (192.168.3.1, 232.1.1.1) and any directly connected sources
sending to 232.1.1.1 will be dropped.
Examples Verifying IPv4 Multicast Forwarding Using the MFIB for Bidir-PIM Networks
This section contains the following examples for verifying multicast forwarding using the MFIB for bidir-PIM networks:
Note
The examples in this section were created in a test environment to provide a conceptual view of the multicast environment.
The IP addresses, interfaces, and other values are shown as examples only. They do not show real-world deployment values.
Bidir-PIM Example Active Sources with Interested Receivers
The following example shows how to verify multicast forwarding using the MFIB for bidir-PIM in a network environment where
there are active sources and interested receivers. This verification example is based on the topology shown in the figures.
Figure 8. Bidir-PIM Example Topology: Active Sources with Interested Receivers
Figure 9. Bidir-PIM Distribution Trees and Multicast Forwarding Paths for the Active Sources with No Interested Receivers Example
For this verification example, the following conditions apply:
Entries for (*, 239.195.0.0/16) are created by the control plane based on the PIM group-to-RP mappings on all routers.
Entries for (*, 239.195.1.1) will only be created when IGMP joins are initiated by interested receivers joining this group.
As a result, all routers along the shared tree between the RP and the last-hop DRs that have interested receivers will have
state for (*, 239.195.1.1).
Note
R1 will not have state for (*, 239.195.1.1) because it is not between the RP and the last-hop DRs.
If both (*,239.195.0.0/26) and (*,239.195.1.1) entries are present in a router, the more specific entry, (*,239.195.1.1)
will be used for forwarding.
All source traffic for this scenario will go to the RP and then out the appropriate interfaces where there are interested
receivers.
Source traffic received by the RP is never sent back out the same interface it was received on.
In general, multicast packet forwarding can be verified by observing the “SW Forwarding” counter in the
show ip mfib output for the most specific entry available in the MFIB. If multicast is being forwarded, this counter will increment.
R1 (First-Hop DR for Source A)
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d02h, expires: 00:02:09
R1# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.1.1 75 1d02h
Ethernet1/0 192.168.254.6 192.168.123.2 65 1d02h
R1# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R1# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R1# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R1# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d02h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R1# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R1# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 4677/10/28/2, Other: 9355/0/9355
Ethernet1/0 Flags: A F
Pkts: 4677/0
Ethernet0/0 Flags: A
Null0 Flags: A
R2 (Router Along the Multicast Forwarding Path)
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d02h, expires: 00:02:45
R2# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet1/0 192.168.254.6 *192.168.123.2 65 1d02h
Serial2/0 192.168.254.6 192.168.26.6 0 1d02h
R2# show ip mroute 239.195.1.1
(*, 239.195.1.1), 02:13:50/00:02:36, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial2/0, RPF nbr 192.168.26.6
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 02:13:50/00:02:36
Serial2/0, Bidir-Upstream/Sparse, 02:13:50/00:00:00
R2# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.26.6 Flags: IA
Ethernet1/0 Flags: F
Serial2/0 Flags: F
R2# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 14693/30/28/6, Other: 0/0/0
Serial2/0 Flags: F
Pkts: 4897/0
Ethernet1/0 Flags: F
Pkts: 9796/0
R2# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d02h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial2/0, RPF nbr: 192.168.26.6
Incoming interface list:
Ethernet1/0, Accepting/Sparse
Serial2/0, Accepting/Sparse
R2# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.26.6 Flags:
Ethernet1/0 Flags: A
Null0 Flags: A
Serial2/0 Flags: A F
R2# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial2/0 Flags: A F
Pkts: 0/0
Ethernet1/0 Flags: A
Null0 Flags: A
R3 (Router Along the Multicast Forwarding Path)
R3# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d02h, expires: 00:02:25
R3# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.3.3 75 1d02h
Ethernet1/0 192.168.254.6 192.168.123.2 65 1d02h
Serial2/0 192.168.254.6 192.168.37.7 65 1d02h
Serial3/0 192.168.254.6 *192.168.34.3 75 1d02h
R3# show ip mroute 239.195.1.1
(*, 239.195.1.1), 02:14:09/00:03:08, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list:
Serial3/0, Forward/Sparse, 02:14:09/00:03:08
Ethernet1/0, Bidir-Upstream/Sparse, 02:14:09/00:00:00
R3# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.123.2 Flags: IA
Serial3/0 Flags: F
Ethernet1/0 Flags: F
R3# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 15263/30/28/6, Other: 0/0/0
Serial3/0 Flags: F
Pkts: 15263/0
Ethernet1/0 Flags: F
Pkts: 0/0
R3# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d02h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Serial3/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R3# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Serial3/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R3# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial3/0 Flags: A
Ethernet1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R4 (Last-Hop DR for Receiver B)
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d02h, expires: 00:02:10
R4# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.4.4 139 1d02h
Serial1/0 192.168.254.6 192.168.34.3 75 1d02h
R4# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.195.1.1 Ethernet0/0 02:14:25 00:02:25 192.168.4.1
R4# show ip mroute 239.195.1.1
(*, 239.195.1.1), 02:14:25/00:02:25, RP 192.168.254.6, flags: BC
Bidir-Upstream: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 02:14:25/00:02:25
Serial1/0, Bidir-Upstream/Sparse, 02:14:25/00:00:00
R4# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.34.3 Flags: IA
Ethernet0/0 Flags: F
Serial1/0 Flags: F
R4# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 15729/30/28/6, Other: 0/0/0
Serial1/0 Flags: F
Pkts: 0/0
Ethernet0/0 Flags: F
Pkts: 15729/0
R4# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d02h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial1/0, RPF nbr: 192.168.34.3
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
R4# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.34.3 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Serial1/0 Flags: A F
R4# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R6 (RP and First-Hop DR for Source B)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.254.6 (?), elected via Auto-RP
Uptime: 1d02h, expires: 00:02:55
R6# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Loopback0 192.168.254.6 *192.168.6.6 0 1d02h
Loopback1 192.168.254.6 *192.168.254.6 0 1d02h
Ethernet0/0 192.168.254.6 *192.168.16.6 0 1d02h
Serial1/0 192.168.254.6 *192.168.67.6 0 1d02h
Serial2/0 192.168.254.6 *192.168.26.6 0 1d02h
R6# show ip mroute 239.195.1.1
(*, 239.195.1.1), 02:14:43/00:02:49, RP 192.168.254.6, flags: B
Bidir-Upstream: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 02:14:35/00:02:49
Serial2/0, Forward/Sparse, 02:14:43/00:02:41
R6# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 0.0.0.0 Flags: IA
Serial1/0 Flags: F
Serial2/0 Flags: F
R6# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 16269/30/28/6, Other: 0/0/0
Serial2/0 Flags: F
Pkts: 10846/0
Serial1/0 Flags: F
Pkts: 10846/0
R6# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d02h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Loopback1, RPF nbr: 192.168.254.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Loopback0, Accepting/Sparse
Loopback1, Accepting/Sparse
R6# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.254.6 Flags:
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Loopback0 Flags: A
Null0 Flags: A
Loopback1 Flags: A F
R6# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback1 Flags: A F
Pkts: 0/0
Loopback0 Flags: A
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
R7 (First-Hop DR for Source C and Last-Hop DR for Receiver A)
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d02h, expires: 00:02:35
R7# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.7.7 65 1d02h
Serial2/0 192.168.254.6 *192.168.37.7 65 1d02h
Serial4/0 192.168.254.6 192.168.67.6 0 1d02h
R7# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.195.1.1 Ethernet0/0 02:14:51 00:02:44 192.168.7.1
R7# show ip mroute 239.195.1.1
(*, 239.195.1.1), 02:14:51/00:02:43, RP 192.168.254.6, flags: BC
Bidir-Upstream: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 02:14:51/00:02:43
Serial4/0, Bidir-Upstream/Sparse, 02:14:51/00:00:00
R7# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.67.6 Flags: IA
Ethernet0/0 Flags: F
Serial4/0 Flags: F
R7# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 16747/30/28/6, Other: 0/0/0
Serial4/0 Flags: F
Pkts: 5582/0
Ethernet0/0 Flags: F
Pkts: 11165/0
R7# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d02h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial4/0, RPF nbr: 192.168.67.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Serial4/0, Accepting/Sparse
R7# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.67.6 Flags:
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Serial4/0 Flags: A F
R7# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0 Flags: A F
Pkts: 0/0
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Bidir-PIM Example Active Sources with No Interested Receivers
The following example shows how to verify multicast forwarding using the MFIB for bidir-PIM in a network environment where
there are active sources with no interested receivers. This verification example is based on the topology shown in the figures.
Figure 10. Bidir-PIM Example Topology: Active Sources with No Interested Receivers
Figure 11. Bidir-PIM Distribution Trees and Multicast Forwarding Path for Active Sources with No Interested Receivers Example
For this verification example, the following conditions apply:
Entries for (*, 239.195.0.0/16) are created by the control plane based on the PIM group-to-RP mappings on all routers.
Because there are no interested receivers, (*, 239.195.0.0/16) will be the only state in the network on all routers.
All source traffic for this example will go to the RP and then be dropped because there are no interested receivers in the
network. In addition, source traffic received by the RP is never sent back out the same interface it was received on.
In general, multicast packet forwarding can be verified by observing the “SW Forwarding” counter in the
show ip mfib output for the most specific entry available in the MFIB. If multicast is being forwarded, this counter will increment.
In this scenario, all traffic stops at the RP because there are no interested receivers. In addition, traffic received by
the RP will be forwarded only to the bidir-PIM RP interface to be dropped.
R1 (First-Hop DR for Source A)
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d03h, expires: 00:02:43
R1# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.1.1 75 1d03h
Ethernet1/0 192.168.254.6 192.168.123.2 65 1d03h
R1# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R1# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R1# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R1# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d03h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R1# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R1# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 34754/10/28/2, Other: 58228/0/58228
Ethernet1/0 Flags: A F
Pkts: 34754/0
Ethernet0/0 Flags: A
Null0 Flags: A
R2
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d03h, expires: 00:02:28
R2# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet1/0 192.168.254.6 *192.168.123.2 65 1d03h
Serial2/0 192.168.254.6 192.168.26.6 0 1d03h
R2# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R2# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R2# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R2# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d03h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial2/0, RPF nbr: 192.168.26.6
Incoming interface list:
Ethernet1/0, Accepting/Sparse
Serial2/0, Accepting/Sparse
R2# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.26.6 Flags:
Ethernet1/0 Flags: A
Null0 Flags: A
Serial2/0 Flags: A F
R2# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 4211/10/28/2, Other: 0/0/0
Serial2/0 Flags: A F
Pkts: 4211/0
Ethernet1/0 Flags: A
Null0 Flags: A
R3
R3# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d03h, expires: 00:02:09
R3# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.3.3 75 1d03h
Ethernet1/0 192.168.254.6 192.168.123.2 65 1d03h
Serial2/0 192.168.254.6 192.168.37.7 65 1d03h
Serial3/0 192.168.254.6 *192.168.34.3 75 1d03h
R3# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
R3# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R3# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R3# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R3# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d03h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Serial3/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R3# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Serial3/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R3# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 3935/0/3935
Serial3/0 Flags: A
Ethernet1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R4
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d03h, expires: 00:02:54
R4# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.4.4 139 1d03h
Serial1/0 192.168.254.6 192.168.34.3 75 1d03h
R4# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
R4# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R4# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R4# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R4# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d03h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial1/0, RPF nbr: 192.168.34.3
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
R4# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.34.3 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Serial1/0 Flags: A F
R4# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R6 (RP and First-Hop DR for Source B)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.254.6 (?), elected via Auto-RP
Uptime: 1d03h, expires: 00:01:59
R6# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Loopback0 192.168.254.6 *192.168.6.6 0 1d03h
Loopback1 192.168.254.6 *192.168.254.6 0 1d03h
Ethernet0/0 192.168.254.6 *192.168.16.6 0 1d03h
Serial1/0 192.168.254.6 *192.168.67.6 0 1d03h
Serial2/0 192.168.254.6 *192.168.26.6 0 1d03h
R6# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R6# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R6# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R6# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d03h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Loopback1, RPF nbr: 192.168.254.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Loopback0, Accepting/Sparse
Loopback1, Accepting/Sparse
R6# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.254.6 Flags:
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Loopback0 Flags: A
Null0 Flags: A
Loopback1 Flags: A F
R6# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 13951/30/28/6, Other: 0/0/0
Loopback1 Flags: A F
Pkts: 13951/0
Loopback0 Flags: A
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
R7 (First-Hop DR for Source C)
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d03h, expires: 00:02:22
R7# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.7.7 65 1d03h
Serial2/0 192.168.254.6 *192.168.37.7 65 1d03h
Serial4/0 192.168.254.6 192.168.67.6 0 1d03h
R7# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
R7# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R7# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R7# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R7# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d03h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial4/0, RPF nbr: 192.168.67.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Serial4/0, Accepting/Sparse
R7# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.67.6 Flags:
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Serial4/0 Flags: A F
R7# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 4917/10/28/2, Other: 0/0/0
Serial4/0 Flags: A F
Pkts: 4917/0
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Bidir-PIM Example No Active Sources with Interested Receivers
The following example shows how to verify multicast forwarding using the MFIB for bidir-PIM in a network environment where
there are no active sources with interested receivers. This verification example is based on the topology shown in the figure.
Figure 12. Bidir-PIM Example Topology: No Active Sources with Interested Receivers
For this verification example, the following conditions apply:
Entries for (*, 239.195.0.0/16) are created by the control plane based on the PIM group-to-RP mappings on all routers.
Entries for (*, 239.195.1.1) will be created only when IGMP joins are initiated by interested receivers joining this group.
As a result, all routers along the shared tree between the RP and the last-hop DRs that have interested receivers will have
state for (*, 239.195.1.1).
Note
R1 will not have state for (*, 239.195.1.1) because it is not between the RP and the last-hop DRs.
In general, multicast packet forwarding can be verified by observing the “SW Forwarding” counter in
show ip mfib command output for the most specific entry available in the MFIB. If multicast is being forwarded, this counter will increment;
however, because there are no active sources in this scenario, this counter will not increment.
R1
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d01h, expires: 00:02:07
R1# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.1.1 75 1d01h
Ethernet1/0 192.168.254.6 192.168.123.2 65 1d01h
R1# show ip mroute 239.195.1.1
Group 239.195.1.1 not found
R1# show ip mrib route 239.195.1.1
No matching routes in MRIB route-DB
R1# show ip mfib 239.195.1.1
Group 239.195.1.1 not found
R1# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d01h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R1# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R1# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Ethernet1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R2
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d01h, expires: 00:02:32
R2# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet1/0 192.168.254.6 *192.168.123.2 65 1d01h
Serial2/0 192.168.254.6 192.168.26.6 0 1d01h
R2# show ip mroute 239.195.1.1
(*, 239.195.1.1), 01:30:22/00:02:50, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial2/0, RPF nbr 192.168.26.6
Outgoing interface list:
Ethernet1/0, Forward/Sparse, 01:30:22/00:02:50
Serial2/0, Bidir-Upstream/Sparse, 01:30:22/00:00:00
R2# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.26.6 Flags: IA
Ethernet1/0 Flags: F
Serial2/0 Flags: F
R2# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial2/0 Flags: F
Pkts: 0/0
Ethernet1/0 Flags: F
Pkts: 0/0
R2# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d01h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial2/0, RPF nbr: 192.168.26.6
Incoming interface list:
Ethernet1/0, Accepting/Sparse
Serial2/0, Accepting/Sparse
R2# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.26.6 Flags:
Ethernet1/0 Flags: A
Null0 Flags: A
Serial2/0 Flags: A F
R2# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial2/0 Flags: A F
Pkts: 0/0
Ethernet1/0 Flags: A
Null0 Flags: A
R3
R3# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d01h, expires: 00:02:17
R3# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.3.3 75 1d01h
Ethernet1/0 192.168.254.6 192.168.123.2 65 1d01h
Serial2/0 192.168.254.6 192.168.37.7 65 1d01h
Serial3/0 192.168.254.6 *192.168.34.3 75 1d01h
R3# show ip mroute 239.195.1.1
(*, 239.195.1.1), 01:30:36/00:03:21, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr 192.168.123.2
Outgoing interface list:
Serial3/0, Forward/Sparse, 01:30:36/00:03:21
Ethernet1/0, Bidir-Upstream/Sparse, 01:30:36/00:00:00
R3# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.123.2 Flags: IA
Serial3/0 Flags: F
Ethernet1/0 Flags: F
R3# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial3/0 Flags: F
Pkts: 0/0
Ethernet1/0 Flags: F
Pkts: 0/0
R3# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d01h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Serial3/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R3# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Serial3/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R3# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial3/0 Flags: A
Ethernet1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R4 (Last-Hop DR for Receiver B)
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d01h, expires: 00:02:02
R4# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.4.4 139 1d01h
Serial1/0 192.168.254.6 192.168.34.3 75 1d01h
R4# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.195.1.1 Ethernet0/0 01:30:51 00:02:56 192.168.4.1
R4# show ip mroute 239.195.1.1
(*, 239.195.1.1), 01:30:51/00:02:56, RP 192.168.254.6, flags: BC
Bidir-Upstream: Serial1/0, RPF nbr 192.168.34.3
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 01:30:51/00:02:56
Serial1/0, Bidir-Upstream/Sparse, 01:30:51/00:00:00
R4# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.34.3 Flags: IA
Ethernet0/0 Flags: F
Serial1/0 Flags: F
R4# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial1/0 Flags: F
Pkts: 0/0
Ethernet0/0 Flags: F
Pkts: 0/0
R4# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d01h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial1/0, RPF nbr: 192.168.34.3
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
R4# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.34.3 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Serial1/0 Flags: A F
R4# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R6 (RP)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.254.6 (?), elected via Auto-RP
Uptime: 1d01h, expires: 00:02:30
R6# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Loopback0 192.168.254.6 *192.168.6.6 0 1d01h
Loopback1 192.168.254.6 *192.168.254.6 0 1d01h
Ethernet0/0 192.168.254.6 *192.168.16.6 0 1d01h
Serial1/0 192.168.254.6 *192.168.67.6 0 1d01h
Serial2/0 192.168.254.6 *192.168.26.6 0 1d01h
R6# show ip mroute 239.195.1.1
(*, 239.195.1.1), 01:31:08/00:03:00, RP 192.168.254.6, flags: B
Bidir-Upstream: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0, Forward/Sparse, 01:31:00/00:03:00
Serial2/0, Forward/Sparse, 01:31:08/00:02:57
R6# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 0.0.0.0 Flags: IA
Serial1/0 Flags: F
Serial2/0 Flags: F
R6# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial2/0 Flags: F
Pkts: 0/0
Serial1/0 Flags: F
Pkts: 0/0
R6# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d01h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Loopback1, RPF nbr: 192.168.254.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Loopback0, Accepting/Sparse
Loopback1, Accepting/Sparse
R6# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.254.6 Flags:
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Loopback0 Flags: A
Null0 Flags: A
Loopback1 Flags: A F
R6# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback1 Flags: A F
Pkts: 0/0
Loopback0 Flags: A
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
R7 (Last-Hop DR for Receiver A)
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 1d01h, expires: 00:02:33
R7# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.7.7 65 1d01h
Serial2/0 192.168.254.6 *192.168.37.7 65 1d01h
Serial4/0 192.168.254.6 192.168.67.6 0 1d01h
R7# show ip igmp groups 239.195.1.1
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.195.1.1 Ethernet0/0 01:31:14 00:02:22 192.168.7.1
R7# show ip mroute 239.195.1.1
(*, 239.195.1.1), 01:31:14/00:02:22, RP 192.168.254.6, flags: BC
Bidir-Upstream: Serial4/0, RPF nbr 192.168.67.6
Outgoing interface list:
Ethernet0/0, Forward/Sparse, 01:31:14/00:02:22
Serial4/0, Bidir-Upstream/Sparse, 01:31:14/00:00:00
R7# show ip mrib route 239.195.1.1
(*,239.195.1.1) RPF nbr: 192.168.67.6 Flags: IA
Ethernet0/0 Flags: F
Serial4/0 Flags: F
R7# show ip mfib 239.195.1.1
(*,239.195.1.1) Flags: IA
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0 Flags: F
Pkts: 0/0
Ethernet0/0 Flags: F
Pkts: 0/0
R7# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 1d01h/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial4/0, RPF nbr: 192.168.67.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Serial4/0, Accepting/Sparse
R7# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.67.6 Flags:
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Serial4/0 Flags: A F
R7# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0 Flags: A F
Pkts: 0/0
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Bidir-PIM Example No Active Sources with No Interested Receivers
The following example shows how to verify multicast forwarding using the MFIB for bidir-PIM in a network environment where
there are no active sources and no interested receivers. This verification example is based on the topology shown in the figure.
Figure 13. Bidir-PIM Example Topology: No Active Sources with No Interested Receivers
For this verification example, the following conditions apply:
Entries for (*, 239.195.0.0/16) are created by the control plane based on the PIM group-to-RP mappings on all routers.
Entries for any group within the range 239.195.0.0/16 will be created only when IGMP joins are initiated by interested receivers
joining that particular group. For example, if a multicast receiver joins the group 239.195.1.1, an entry for (*, 239.195.1.1)
will be created on all routers along the shared tree.
Because there are no interested receivers, (*, 239.195.0.0/16) will be the only state in the network on all routers.
In general, multicast packet forwarding can be verified by observing the “SW Forwarding” counter in
show ip mfib command output for the most specific entry available in the MFIB. If multicast is being forwarded, this counter will increment;
however, because there are no active sources in this scenario, this counter will not increment.
R1
R1# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 22:06:01, expires: 00:02:30
R1# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 22:06:01/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R1# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R1# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Ethernet1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R1# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.1.1 75 22:06:01
Ethernet1/0 192.168.254.6 192.168.123.2 65 22:06:01
R2
R2# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 22:09:00, expires: 00:02:30
R2# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 22:09:00/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial2/0, RPF nbr: 192.168.26.6
Incoming interface list:
Ethernet1/0, Accepting/Sparse
Serial2/0, Accepting/Sparse
R2# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.26.6 Flags:
Ethernet1/0 Flags: A
Null0 Flags: A
Serial2/0 Flags: A F
R2# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial2/0 Flags: A F
Pkts: 0/0
Ethernet1/0 Flags: A
Null0 Flags: A
R2# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet1/0 192.168.254.6 *192.168.123.2 65 22:09:00
Serial2/0 192.168.254.6 192.168.26.6 0 22:09:00
R3
R3# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 22:09:20, expires: 00:02:12
R3# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 22:09:20/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Ethernet1/0, RPF nbr: 192.168.123.2
Incoming interface list:
Serial3/0, Accepting/Sparse
Ethernet1/0, Accepting/Sparse
R3# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.123.2 Flags:
Serial3/0 Flags: A
Null0 Flags: A
Ethernet1/0 Flags: A F
R3# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial3/0 Flags: A
Ethernet1/0 Flags: A F
Pkts: 0/0
Null0 Flags: A
R3# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet1/0 192.168.254.6 192.168.123.2 65 22:09:20
Serial2/0 192.168.254.6 192.168.37.7 65 22:09:20
Serial3/0 192.168.254.6 *192.168.34.3 75 22:09:20
R4
R4# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 22:09:47, expires: 00:02:42
R4# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 22:09:47/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial1/0, RPF nbr: 192.168.34.3
Incoming interface list:
Ethernet0/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
R4# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.34.3 Flags:
Ethernet0/0 Flags: A
Null0 Flags: A
Serial1/0 Flags: A F
R4# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial1/0 Flags: A F
Pkts: 0/0
Ethernet0/0 Flags: A
Null0 Flags: A
R4# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.4.4 139 22:09:47
Serial1/0 192.168.254.6 192.168.34.3 75 22:09:47
R6 (RP)
R6# show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.254.6 (?), elected via Auto-RP
Uptime: 22:11:08, expires: 00:02:48
R6# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 22:11:08/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Loopback1, RPF nbr: 192.168.254.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Serial1/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Loopback1, Accepting/Sparse
R6# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.254.6 Flags:
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Loopback1 Flags: A F
R6# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Loopback1 Flags: A F
Pkts: 0/0
Serial2/0 Flags: A
Serial1/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
R6# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Loopback1 192.168.254.6 *192.168.254.6 0 22:11:08
Ethernet0/0 192.168.254.6 *192.168.16.6 0 22:11:08
Serial1/0 192.168.254.6 *192.168.67.6 0 22:11:08
Serial2/0 192.168.254.6 *192.168.26.6 0 22:11:08
R7
R7# show ip pim rp mapping
PIM Group-to-RP Mappings
Group(s) 239.195.0.0/16
RP 192.168.254.6 (?), v2v1, bidir
Info source: 192.168.6.6 (?), elected via Auto-RP
Uptime: 22:10:23, expires: 00:02:04
R7# show ip mroute 239.195.0.0/16
(*,239.195.0.0/16), 22:10:23/-, RP 192.168.254.6, flags: B
Bidir-Upstream: Serial4/0, RPF nbr: 192.168.67.6
Incoming interface list:
Serial2/0, Accepting/Sparse
Ethernet0/0, Accepting/Sparse
Serial4/0, Accepting/Sparse
R7# show ip mrib route 239.195.0.0/16
(*,239.195.0.0/16) RPF nbr: 192.168.67.6 Flags:
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
Serial4/0 Flags: A F
R7# show ip mfib 239.195.0.0/16
(*,239.195.0.0/16) Flags:
SW Forwarding: 0/0/0/0, Other: 0/0/0
Serial4/0 Flags: A F
Pkts: 0/0
Serial2/0 Flags: A
Ethernet0/0 Flags: A
Null0 Flags: A
R7# show ip pim interface df
* implies this system is the DF
Interface RP DF Winner Metric Uptime
Ethernet0/0 192.168.254.6 *192.168.7.7 65 22:10:23
Serial2/0 192.168.254.6 *192.168.37.7 65 22:10:23
Serial4/0 192.168.254.6 192.168.67.6 0 22:10:23
Additional References
Related Documents
Related Topic
Document Title
MFIB overview concepts and MFIB/MRIB entry and interface flag descriptions
“ Multicast Forwarding Information Base Overview ”
Overview of the IP multicast technology area
“ IP Multicast Technology Overview ”
Concepts, tasks, and examples for configuring an IP multicast network using PIM
“ Configuring Basic IP Multicast ”
IP multicast commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples
Cisco IOS IP Multicast Command Reference
Standards
Standard
Title
No new or modified standards are supported, and support for existing standards has not been modified.
--
MIBs
MIB
MIBs Link
No new or modified MIBs are supported, and support for existing MIBs has not been modified.
To locate and download MIBs for selected platforms, Cisco IOS software releases, and feature sets, use Cisco MIB Locator
found at the following URL:
No new or modified RFCs are supported, and support for existing RFCs has not been modified.
--
Technical Assistance
Description
Link
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and
resolving technical issues with Cisco products and technologies.
To receive security and technical information about your products, you can subscribe to various services, such as the Product
Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.
Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.
Feature Information for Verifying IPv4 Multicast Forwarding Using the MFIB
The following table provides release information about the feature or features described in this module. This table lists
only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise,
subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco
Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 11. Feature Information for Verifying IPv4 Multicast Forwarding Using the MFIB
Feature Name
Releases
Feature Information
IPv4 Multicast Support of the MFIB
15.0(1)M 12.2(33)SRE
The MFIB architecture provides modularity and separation between the multicast control plane (PIM and IGMP) and the multicast
forwarding plane (MFIB). This architecture is used in Cisco IOS IPv6 and Cisco IOS XR multicast implementations. With the
introduction of the IPv4 MFIB infrastructure, the Cisco IOS IPv4 multicast implementation has been enhanced, making the MFIB
forwarding model the only forwarding engine used.
The following commands were introduced or modified:
clear ip mfib counters ,debug ip mcache ,
debug ip mfib adjacency ,
debug ip mfib db ,
debug ip mfib fs ,
debug ip mfib init ,
debug ip mfib interface ,
debug ip mfib mrib ,
debug ip mfib pak ,
debug ip mfib platform ,
debug ip mfib ppr ,
debug ip mfib ps ,
debug ip mfib signal ,
debug ip mfib table ,
debug ip mpacket ,
debug ip mrib ,
ip mfib ,
ip mfib cef ,ip mfib forwarding ,
ip mroute-cache ,
ip multicast cache-headers ,ip multicast rate-limit ,
ip multicast ttl-threshold ,ip pim register-rate-limit ,
show ip mcache ,
show ip mfib ,show ip mfib active ,
show ip mfib count ,
show ip mfib interface ,
show ip mfib route ,
show ip mfib status ,show ip mfib summary ,
show ip pim interface ,
show ip pim tunne l.
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