Introduzione
In questo documento viene descritto come inoltrare un flusso multicast che proviene da un'origine in un'origine VRF (Virtual Routing and Forwarding) e va verso gli utenti nel ricevitore VRF senza causare perdite di percorso unicast tra VRF.
Prerequisiti
Requisiti
Cisco raccomanda la conoscenza delle funzionalità PIM e ASM.
Componenti usati
Il riferimento delle informazioni contenute in questo documento è ASR1000.
Le informazioni discusse in questo documento fanno riferimento a dispositivi usati in uno specifico ambiente di emulazione. Su tutti i dispositivi menzionati nel documento la configurazione è stata ripristinata ai valori predefiniti. Se la rete è operativa, valutare attentamente eventuali conseguenze derivanti dall'uso dei comandi.
Esempio di rete
Configurazioni
Genera flusso multicast UDP sull'origine.
Source#
ip sla 1
udp-echo 239.1.1.1 2000 source-ip 10.1.1.1
ip sla schedule 1 life forever start-time now
Il ricevitore è configurato con IGMP e invia i rapporti di appartenenza a IGMP.
Il router ASR1000 sta eseguendo l'inoltro del traffico multicast tra vrf. Il loopback 1 in 'origine' VRF è l'RP per entrambi i VRF.
ASR1000#
ip vrf source
rd 1:1
!
ip vrf receiver
rd 2:2
!
ip multicast-routing vrf source distributed
ip multicast-routing vrf receiver distributed
ip pim vrf source rp-address 1.1.1.1
ip pim vrf receiver rp-address 1.1.1.1
interface Loopback1
ip vrf forwarding source
ip address 1.1.1.1 255.255.255.255
ip pim sparse-mode
interface GigabitEthernet0/0/0
ip vrf forwarding source
ip address 10.1.1.2 255.255.255.0
ip pim sparse-mode
interface GigabitEthernet0/0/1
ip vrf forwarding receiver
ip address 20.1.1.2 255.255.255.0
ip pim sparse-mode
(S, G) voce non formata in vrf 'receive' per il momento.
ASR1002-1#show ip mroute vrf source
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group,
G - Received BGP C-Mroute, g - Sent BGP C-Mroute,
N - Received BGP Shared-Tree Prune, n - BGP C-Mroute suppressed,
Q - Received BGP S-A Route, q - Sent BGP S-A Route,
V - RD & Vector, v - Vector, p - PIM Joins on route,
x - VxLAN group, c - PFP-SA cache created entry,
* - determined by Assert
Outgoing interface flags: H - Hardware switched, A - Assert winner, p - PIM Join
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.1), 00:05:01/stopped, RP 1.1.1.1, flags: SPF
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list: Null
(10.1.1.1, 239.1.1.1), 00:05:01/00:02:26, flags: PFT
Incoming interface: GigabitEthernet0/0/0, RPF nbr 0.0.0.0
Outgoing interface list: Null
(*, 224.0.1.40), 00:07:03/00:02:59, RP 1.1.1.1, flags: SJCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Loopback1, Forward/Sparse, 00:07:01/00:02:59
ASR1002-X-1#sh ip mroute vrf receiver
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group,
G - Received BGP C-Mroute, g - Sent BGP C-Mroute,
N - Received BGP Shared-Tree Prune, n - BGP C-Mroute suppressed,
Q - Received BGP S-A Route, q - Sent BGP S-A Route,
V - RD & Vector, v - Vector, p - PIM Joins on route,
x - VxLAN group, c - PFP-SA cache created entry,
* - determined by Assert, # - iif-starg configured on rpf intf,
e - encap-helper tunnel flag
Outgoing interface flags: H - Hardware switched, A - Assert winner, p - PIM Join
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.1), 00:03:23/00:02:44, RP 1.1.1.1, flags: SJC
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
GigabitEthernet0/0/1, Forward/Sparse, 00:03:23/00:02:44
Per risolvere questo problema, è necessario selezionare un VRF in modo da superare il controllo RPF.
ip access-list standard 1
permit 239.1.1.1 log
exit
ip multicast vrf receiver rpf select vrf source group-list 1
Verifica
Per verificare che la configurazione funzioni correttamente, consultare questa sezione.
Dopo aver eseguito i passaggi descritti in precedenza, è possibile visualizzare l'avanzamento Multicast sul ricevitore.
Receiver#show flow monitor test cache format table
Cache type: Normal (Platform cache)
Cache size: 200000
Current entries: 1
High Watermark: 3
Flows added: 50
Flows aged: 49
- Inactive timeout ( 15 secs) 49
IPV4 SRC ADDR IPV4 DST ADDR TRNS SRC PORT TRNS DST PORT INTF INPUT FLOW SAMPLER ID IP TOS IP PROT ip src as ip dst as ipv4 next hop addr ipv4 src mask ipv4 dst mask tcp flags intf output bytes pkts time first time last
=============== =============== ============= ============= ==================== =============== ====== ======= ========= ========= ================== ============= ============= ========= ==================== ========== ========== ============ ============
10.1.1.1 239.1.1.1 57314 1967 Gi0/0/3 0 0x00 17 0 0 0.0.0.0 /0 /0 0x00 Null 80 1 11:09:08.082 11:09:08.082
Packet Capture sul ricevitore.
(S, G) nel ricevitore VRF.
ASR1002-1#show ip mroute vrf receiver 239.1.1.1
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected, L - Local,
P - Pruned, R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPT,
M - MSDP created entry, E - Extranet, X - Proxy Join Timer Running,
A - Candidate for MSDP Advertisement, U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender, Y - Joined MDT-data group,
y - Sending to MDT-data group, G - Received BGP C-Mroute, g - Sent BGP C-Mroute,
N - Received BGP Shared-Tree Prune, n - BGP C-Mroute suppressed,
Q - Received BGP S-A Route, q - Sent BGP S-A Route, V - RD & Vector, v - Vector,
p - PIM Joins on route, x - VxLAN group, c - PFP-SA cache created entry,
* - determined by Assert Outgoing interface flags: H - Hardware switched,
A - Assert winner, p - PIM Join
Timers: Uptime/Expires
Interface state:
Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.1), 00:21:36/stopped, RP 1.1.1.1, flags: SJC
Incoming interface: Loopback1, RPF nbr 1.1.1.1, using vrf source
Outgoing interface list:
GigabitEthernet0/0/1, Forward/Sparse, 00:21:36/00:02:43
(10.1.1.1, 239.1.1.1), 00:03:55/stopped, flags: T
Incoming interface: GigabitEthernet0/0/0, RPF nbr 0.0.0.0, using vrf source
Outgoing interface list:
GigabitEthernet0/0/1, Forward/Sparse, 00:03:55/00:02:43
ASR1002-1#show ip mroute vrf source 239.1.1.1
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group,
G - Received BGP C-Mroute, g - Sent BGP C-Mroute,
N - Received BGP Shared-Tree Prune, n - BGP C-Mroute suppressed,
Q - Received BGP S-A Route, q - Sent BGP S-A Route,
V - RD & Vector, v - Vector, p - PIM Joins on route,
x - VxLAN group, c - PFP-SA cache created entry,
* - determined by Assert
Outgoing interface flags: H - Hardware switched, A - Assert winner, p - PIM Join
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.1.1.1), 00:22:36/stopped, RP 1.1.1.1, flags: SJCFE
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list: Null
Extranet receivers in vrf receiver:
(*, 239.1.1.1), 00:21:54/stopped, RP 1.1.1.1, OIF count: 1, flags: SJC
(10.1.1.1, 239.1.1.1), 00:04:14/00:02:55, flags: FTE
Incoming interface: GigabitEthernet0/0/0, RPF nbr 0.0.0.0
Outgoing interface list: Null
Extranet receivers in vrf receiver:
(10.1.1.1, 239.1.1.1), 00:04:14/stopped, OIF count: 1, flags: T
ASR1002-1#show ip mfib vrf receiver 239.1.1.1
Entry Flags: C - Directly Connected, S - Signal, IA - Inherit A flag,
ET - Data Rate Exceeds Threshold, K - Keepalive
DDE - Data Driven Event, HW - Hardware Installed
ME - MoFRR ECMP entry, MNE - MoFRR Non-ECMP entry, MP - MFIB
MoFRR Primary, RP - MRIB MoFRR Primary, P - MoFRR Primary
MS - MoFRR Entry in Sync, MC - MoFRR entry in MoFRR Client.
I/O Item Flags: IC - Internal Copy, NP - Not platform switched,
NS - Negate Signalling, SP - Signal Present,
A - Accept, F - Forward, RA - MRIB Accept, RF - MRIB Forward,
MA - MFIB Accept, A2 - Accept backup,
RA2 - MRIB Accept backup, MA2 - MFIB Accept backup
Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kbits per second
Other counts: Total/RPF failed/Other drops
I/O Item Counts: HW Pkt Count/FS Pkt Count/PS Pkt Count Egress Rate in pps
VRF receiver
(*,239.1.1.1) Flags: C HW
SW Forwarding: 0/0/0/0, Other: 0/0/0
HW Forwarding: 0/0/0/0, Other: 1/1/0
GigabitEthernet0/0/1 Flags: NS
(10.1.1.1,239.1.1.1) Flags: HW
SW Forwarding: 0/0/0/0, Other: 0/0/0
HW Forwarding: 15/0/94/0, Other: 0/0/0
GigabitEthernet0/0/1 Flags: NS
Inoltre, non vi è alcuna voce unicast nel ricevitore VRF RIB per RP e IP sorgente.
ASR1002-1#show ip route vrf receiver 1.1.1.1
Routing Table: receiver % Network not in table
ASR1002-1#show ip route vrf receiver 10.1.1.1
Routing Table: receiver % Network not in table
Pertanto RPF indica come non riuscito, il che è previsto, ma il traffico multicast verrà inoltrato.
ASR1002-1#show ip rpf vrf receiver 1.1.1.1
failed, no route exists
ASR1002-1#show ip rpf vrf receiver 10.1.1.1
failed, no route exists
Esiste un altro modo per raggiungere questo obiettivo, ovvero:
ip mroute vrf receiver 10.1.1.0 255.255.255.0 fallback-lookup vrf source
ip mroute vrf receiver 1.1.1.1 255.255.255.255 fallback-lookup vrf source
In questo caso, il controllo RPF avrà esito positivo.
ASR1002-1#show ip rpf vrf receiver 1.1.1.1
RPF information for ? (1.1.1.1)
RPF interface: Loopback1
RPF neighbor: ? (1.1.1.1) - directly connected
RPF route/mask: 1.1.1.1/32
RPF type: multicast (connected)
Doing distance-preferred lookups across tables
Using Extranet RPF Rule: Static Fallback Lookup, RPF VRF: source
RPF topology: ipv4 multicast base
ASR1002-1#show ip rpf vrf receiver 10.1.1.1
RPF information for ? (10.1.1.1)
RPF interface: GigabitEthernet0/0/0
RPF neighbor: ? (10.1.1.1) - directly connected
RPF route/mask: 10.1.1.0/24
RPF type: multicast (connected)
Doing distance-preferred lookups across tables
Using Extranet RPF Rule: Static Fallback Lookup, RPF VRF: source
RPF topology: ipv4 multicast base
Tuttavia, è possibile utilizzare il comando RPF select o il comando fallback lookup, entrambi in ultima analisi soddisfano il nostro scopo.
Risoluzione dei problemi
Al momento non sono disponibili informazioni specifiche per la risoluzione dei problemi di questa configurazione.