Examples
The following is sample output from the show
ip
nhrp command. This output shows the NHRP group received from the spoke:
Router# show ip nhrp
10.0.0.2/32 via 10.0.0.2, Tunnel0 created 00:17:49, expire 00:01:30
Type: dynamic, Flags: unique registered used
NBMA address: 172.17.0.2
Group: test-group-0
10.0.0.3/32 via 10.0.0.3, Tunnel0 created 00:00:11, expire 01:59:48
Type: dynamic, Flags: unique registered used
NBMA address: 172.17.0.3
Group: test-group-0
11.0.0.2/32 via 11.0.0.2, Tunnel1 created 00:17:49, expire 00:02:10
Type: dynamic, Flags: unique registered used
NBMA address: 172.17.0.2
Group: test-group-1
The following is sample output from the show
ip
nhrp
shortcut command:
Router#show ip nhrp shortcut
10.1.1.1/24 via 1.1.1.22 Tunnel0 created 00:00:05, expire 00:02:24
Type: dynamic, Flags: router rib
NBMA address: 10.12.1.1
10.1.1.2/24 via 1.1.1.22 Tunnel0 created 00:00:05, expire 00:02:24
Type: dynamic, Flags: router rib nho
NBMA address: 10.12.1.2
The following is sample output from the show
ip
nhrp
detail command:
Router# show ip nhrp detail
10.1.1.1/8 via 10.2.1.1, Tunnel1 created 00:46:29, never expire
Type: static, Flags: used
NBMA address: 10.12.1.1
10.1.1.2/8 via 10.2.1.2, Tunnel1 created 00:00:12, expire 01:59:47
Type: dynamic, Flags: authoritative unique nat registered used
NBMA address: 10.12.1.2
10.1.1.4, Tunnel1 created 00:00:07, expire 00:02:57
Type: incomplete, Flags: negative
Cache hits: 4
The following is sample output from the show
ip
nhrp
local command:
Router# show ip nhrp local
Load for five secs: 100%/36%; one minute: 99%; five minutes: 99%
No time source, *12:44:19.808 UTC Tue Dec 7 2021
192.168.0.0/16 via 10.0.0.1
Tunnel0 created 00:00:08, never expire
Type: static, Flags: local
NBMA address: 1.1.1.1
(no-socket)
The following is sample output from the show
ip
nhrp
local
detail command:
Router# show ip nhrp local detail
Load for five secs: 100%/48%; one minute: 99%; five minutes: 99%
No time source, *12:44:52.971 UTC Tue Dec 7 2021
192.168.0.0/16 via 10.0.0.1
Tunnel0 created 00:00:41, never expire
Type: static, Flags: local
NBMA address: 1.1.1.1
Preference: 255
(no-socket)
The following is sample output from the show
ip
nhrp
local
dynamic command:
Router# show ip nhrp local dynamic
Load for five secs: 99%/29%; one minute: 99%; five minutes: 99%
No time source, *12:45:15.567 UTC Tue Dec 7 2021
The following is sample output from the show
ip
nhrp
remote command:
Router# show ip nhrp remote
Load for five secs: 99%/16%; one minute: 99%; five minutes: 99%
No time source, *12:45:36.789 UTC Tue Dec 7 2021
10.1.0.1/32 via 10.1.0.1
Tunnel0 created 00:08:41, expire 00:12:55
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.1.1
10.1.0.3/32 via 10.1.0.3
Tunnel0 created 00:17:30, expire 00:12:36
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.3.1
10.1.0.4/32 via 10.1.0.4
Tunnel0 created 00:13:01, expire 00:14:31
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.4.1
10.1.0.5/32 via 10.1.0.5
Tunnel0 created 00:02:08, expire 00:12:51
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.5.1
10.1.0.6/32 via 10.1.0.6
Tunnel0 created 00:07:19, expire 00:07:41
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.6.1
10.1.0.7/32 via 10.1.0.7
Tunnel0 created 00:07:27, expire 00:14:57
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.7.1
10.1.0.8/32 via 10.1.0.8
Tunnel0 created 00:08:30, expire 00:06:31
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.8.1
10.1.0.9/32 via 10.1.0.9
Tunnel0 created 00:06:22, expire 00:12:34
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.9.1
10.1.0.10/32 via 10.1.0.10
Tunnel0 created 00:13:05, expire 00:11:14
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.10.1
10.1.0.11/32 via 10.1.0.11
Tunnel0 created 00:12:41, expire 00:06:29
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.11.1
10.1.0.12/32 via 10.1.0.12
Tunnel0 created 00:07:07, expire 00:07:52
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.12.1
10.1.0.13/32 via 10.1.0.13
Tunnel0 created 00:13:01, expire 00:14:14
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.13.1
10.1.0.14/32 via 10.1.0.14
Tunnel0 created 00:14:01, expire 00:00:58
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.14.1
10.1.0.15/32 via 10.1.0.15
Tunnel0 created 00:00:56, expire 00:14:03
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.15.1
10.1.0.16/32 via 10.1.0.16
Tunnel0 created 00:13:01, expire 00:11:07
The following is sample output from the show
ip
nhrp
remote
detail command:
Router# show ip nhrp remote detail
Load for five secs: 99%/27%; one minute: 99%; five minutes: 99%
No time source, *12:45:49.796 UTC Tue Dec 7 2021
10.1.0.1/32 via 10.1.0.1
Tunnel0 created 00:08:54, expire 00:12:42
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.1.1
Preference: 192
10.1.0.3/32 via 10.1.0.3
Tunnel0 created 00:17:43, expire 00:12:23
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.3.1
Preference: 192
10.1.0.4/32 via 10.1.0.4
Tunnel0 created 00:13:14, expire 00:14:18
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.4.1
Preference: 192
10.1.0.5/32 via 10.1.0.5
Tunnel0 created 00:02:21, expire 00:12:38
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.5.1
Preference: 192
10.1.0.6/32 via 10.1.0.6
Tunnel0 created 00:07:32, expire 00:07:28
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.6.1
Preference: 192
10.1.0.7/32 via 10.1.0.7
Tunnel0 created 00:07:40, expire 00:14:44
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.7.1
Preference: 192
10.1.0.8/32 via 10.1.0.8
Tunnel0 created 00:08:43, expire 00:14:47
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.8.1
Preference: 192
10.1.0.9/32 via 10.1.0.9
Tunnel0 created 00:06:35, expire 00:12:21
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.9.1
Preference: 192
10.1.0.10/32 via 10.1.0.10
Tunnel0 created 00:13:18, expire 00:11:01
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.10.1
Preference: 192
10.1.0.11/32 via 10.1.0.11
Tunnel0 created 00:12:54, expire 00:06:16
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.11.1
Preference: 192
10.1.0.12/32 via 10.1.0.12
Tunnel0 created 00:07:20, expire 00:07:39
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.12.1
Preference: 192
10.1.0.13/32 via 10.1.0.13
Tunnel0 created 00:13:14, expire 00:14:01
Type: dynamic, Flags: registered nhop bfd
The following is sample output from the show
ip
nhrp
remote
dynamic command:
Router# show ip nhrp remote dynamic
Load for five secs: 100%/12%; one minute: 99%; five minutes: 99%
No time source, *12:48:52.151 UTC Tue Dec 7 2021
10.1.0.1/32 via 10.1.0.1
Tunnel0 created 00:11:56, expire 00:12:31
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.1.1
10.1.0.2/32 via 10.1.0.2
Tunnel0 created 00:02:46, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.2.1
10.1.0.3/32 via 10.1.0.3
Tunnel0 created 00:20:45, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.3.1
10.1.0.4/32 via 10.1.0.4
Tunnel0 created 00:16:16, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.4.1
10.1.0.5/32 via 10.1.0.5
Tunnel0 created 00:05:23, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.5.1
10.1.0.6/32 via 10.1.0.6
Tunnel0 created 00:10:34, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.6.1
10.1.0.7/32 via 10.1.0.7
Tunnel0 created 00:10:42, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.7.1
10.1.0.8/32 via 10.1.0.8
Tunnel0 created 00:11:45, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.8.1
10.1.0.9/32 via 10.1.0.9
Tunnel0 created 00:09:38, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.9.1
10.1.0.10/32 via 10.1.0.10
Tunnel0 created 00:16:20, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.10.1
10.1.0.11/32 via 10.1.0.11
Tunnel0 created 00:15:56, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.11.1
10.1.0.12/32 via 10.1.0.12
Tunnel0 created 00:10:23, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.12.1
10.1.0.13/32 via 10.1.0.13
Tunnel0 created 00:16:16, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.13.1
10.1.0.14/32 via 10.1.0.14
Tunnel0 created 00:17:16, expire 00:12:32
Type: dynamic, Flags: registered nhop bfd
NBMA address: 11.0.14.1
10.1.0.15/32 via 10.1.0.15
Tunnel0 created 00:04:11, expire 00:12:32
The following is sample output from the show
ip
nhrp
remote
self command:
Router# show ip nhrp remote dynamic
Load for five secs: 55%/3%; one minute: 62%; five minutes: 87%
No time source, *12:50:24.793 UTC Tue Dec 7 2021
10.0.0.1/32 via 10.0.0.1
Tunnel0 created 06:46:47, never expire
Type: static, Flags: router unique local
NBMA address: 1.1.1.1
(no-socket)
Metadata Exchange Framework:
Type State
1 Reset
MEF ext data:0x0
2 Reset
MEF ext data:0x0
3 Reset
MEF ext data:0x0
The following is sample output from the show
ip
nhrp
remote
summary command:
Router# show ip nhrp remote summary
Load for five secs: 20%/0%; one minute: 50%; five minutes: 79%
No time source, *12:51:38.026 UTC Tue Dec 7 2021
IP NHRP cache 10000 entries, 7680000 bytes
1 static 9999 dynamic 0 incomplete
9999 Remote
0 static 9999 dynamic 0 incomplete
9999 nhop 9999 bfd
0 default 0 temporary
0 route
0 rib (0 H 0 nho)
0 bgp
0 lfib
1 Local
1 static 0 dynamic 0 incomplete
0 lfib
The following is sample output from the show
ip
nhrp
remote
static
tu1 command:
Router# show ip nhrp remote static tu1
10.0.0.1/32 (VPN1) via 10.0.0.1
Tunnel1 created 1d06h, never expire
Type: static, Flags: bfd
NBMA address: 1.1.1.1
spoke1#sh ip nhrp remote static tu11
10.0.0.1/32 (VPN11) via 10.0.0.1
Tunnel11 created 1d06h, never expire
Type: static, Flags: bfd
NBMA address: 1.1.1.1
The table below describes the significant fields shown in the displays.
Table 8. show ip nhrp Field Descriptions
Field
|
Description
|
10.1.1.1/8
|
Target network.
|
via 10.2.1.1
|
Next Hop to reach the target network.
|
Tunnel1
|
Interface through which the target network is reached.
|
created 00:00:12
|
Length of time since the entry was created (hours:minutes:seconds).
|
expire 01:59:47
|
Time remaining until the entry expires (hours:minutes:seconds).
|
never expire
|
Indicates that static entries never expire.
|
Type
|
-
dynamic--NHRP mapping is obtained dynamically. The mapping entry is created using information from the NHRP resolution and
registrations.
-
static--NHRP mapping is configured statically. Entries configured by the ip
nhrp
map command are marked static.
-
incomplete--The NBMA address is not known for the target network.
|
NBMA address
|
Nonbroadcast multiaccess address of the next hop. The address format is appropriate for the type of network being used: ATM,
Ethernet, Switched Multimegabit Data Service (SMDS), or multipoint tunnel.
|
Flags
|
-
authoritative--Indicates that the NHRP information was obtained directly from the Next Hop Server or router that maintains
and is authoritative for the NBMA-to-IP address mapping for a particular destination.
-
implicit--Indicates that the local node learned about the NHRP mapping entries from the source mapping information of an
NHRP resolution request received by the local router, or from an NHRP resolution packet being forwarded through the local
router.
-
local--Indicates NHRP mapping entries that are for networks local to this router (that is, serviced by this router). These
flag entries are created when this router answers an NHRP resolution request that has this information and is used to store
the transport (tunnel) IP address of all the other NHRP nodes to which it has sent this information. If for some reason this
router loses access to this local network (that is, it can no longer service this network), it sends an NHRP purge message
to all remote NHRP nodes that are listed in the “local” entry (in show
ip
nhrp
detail command output) to tell the remote nodes to clear this information from their NHRP mapping tables. This local mapping entry
times out of the local NHRP mapping database at the same time that this information (from the NHRP resolution reply) would
time out of the NHRP mapping database on the remote NHRP nodes.
-
nat--Indicates that the remote node (NHS client) supports the new NHRP NAT extension type for dynamic spoke-spoke tunnels
to/from spokes behind a NAT router. This marking does not indicate that the spoke (NHS client) is behind a NAT router.
|
Flags (continued)
|
-
negative--For negative caching, indicates that the requested NBMA mapping has not yet been or could not be obtained. When
NHRP sends an NHRP resolution request, an incomplete (negative) NHRP mapping entry for the address is inserted in the resolution
request. This insertion suppresses any more triggering of NHRP resolution requests while the resolution request is being resolved.
If configured, any encryption parameters (IKE/IPsec) for the tunnel are negotiated.
-
(no socket)--Indicates that the NHRP mapping entries will not trigger IPsec to set up encryption because data traffic does
not need to use this tunnel. Later, if data traffic needs to use this tunnel, the flag will change from a “(no socket)” to
a “(socket)” entry and IPsec will be triggered to set up the encryption for this tunnel. Local and implicit NHRP mapping entries
are always initially marked as “(no socket).”
By default, NHRP caches source information from NHRP resolution request or replies as they go through the system. To allow
this caching to continue, but not have the entry create an IPsec socket, they are marked as (no socket). If this was not done
there would be extra IPsec sockets from the hubs to the various spokes that either were not used or were used for only one
or two packets while a direct spoke-to-spoke tunnel was being built. Data packets and NHRP packets that arrive on the tunnel
interface and are forwarded back out the tunnel interface are not allowed to use the (no socket) NHRP mappings for forwarding.
Because, in this case, the router is an intermediate node in the path between the two endpoints and we only want to create
short-cut tunnels between the initial entrance and final exit point of the DMVPN (NBMA) network and not between any intermediate
nodes. If at some point the router receives a data packet that has a source interface that is not the tunnel interface and
it would use the (no socket) mapping entry, the router converts the (no socket) entry to a (socket) entry. In this case, this
router is the entrance (or exit) point of the NBMA (for this traffic stream).
|
Flags (continued)
|
-
(no socket) (continued)--These (no socket) mapping entries are marked (non-authoritative); only mappings from NHRP registrations
are marked (authoritative). The NHRP resolution requests are also marked (authoritative), which means that the NHRP resolution
request can be answered only from an (authoritative) NHRP mapping entry. A (no socket) mapping entry will not be used to answer
an NHRP resolution request and the NHRP resolution request will be forwarded to the NHS of the nodes .
-
registered--Indicates that the mapping entry was created in response to an NHRP registration request. Although registered
mapping entries are dynamic entries, they may not be refreshed through the “used” mechanism. Instead, these entries are refreshed
by another NHRP registration request with the same transport (tunnel) IP to NBMA address mapping. The Next Hop Client (NHC)
periodically sends NHRP registration requests to keep these mappings from expiring.
-
router--Indicates that NHRP mapping entries for a remote router (that is accessing a network or host behind the remote router)
are marked with the router flag.
-
unique--NHRP registration requests have the unique flag set on by default. This flag indicates that an NHRP mapping entry
cannot be overwritten by a mapping entry that has the same IP address and a different NBMA address. When a spoke has a statically
configured outside IP (NBMA) address, this is used to keep another spoke that is mis-configured with the same transport (tunnel)
IP address from overwriting this entry. If a spoke has a dynamic outside IP (NBMA) address, you can configure the ip
nhrp
registration
no-unique command on the spoke to clear this flag. This configuration allows the registered NHRP mapping entry for that spoke on the
hub to be overwritten with a new NBMA address. This is necessary in this case because the spoke's outside IP (NBMA) address
can change at any time. If the “unique” flag was set, the spoke would have to wait for the mapping entry on the hub to time
out before it could register its new (NBMA) mapping.
|
Flags (continued)
|
-
used--When data packets are process-switched and this mapping entry was used, the mapping entry is marked as used. The mapping
database is checked every 60 seconds. If the used flag is set and more than 120 seconds remain until expire time, the used
flag is cleared. If fewer than 120 seconds are left, this mapping entry is “refreshed” by the transmission of another NHRP
resolution request.
Note
|
When using DMVPN Phase 3 in 12.4(6)T, CEF switched packets will also set the “used” flag, and these entries will be timed
out and refreshed as described in the “used” flag description above.
|
|