DMVPN tunnel uptime

[Roger De Couto]

Hi guys,

I've configured a DMVPN (phase 2) with IPSec network and ran the 'show dmvpn' command and got the following output..

R1# show dmvpn
...

Tunnel0, Type:Hub, NHRP Peers:3, 
 # Ent  Peer NBMA Addr Peer Tunnel Add State  UpDn Tm Attrb
 ----- --------------- --------------- ----- -------- -----
 1     172.16.25.2     192.168.0.2    UP 00:35:28 D    
 1     172.16.35.2     192.168.0.3    UP 00:32:26 D    
 

My question is, how long will a tunnel stay 'up' assuming the physical link & remote site is stable and we do not manually force the tunnel to drop.

Does the tunnel automatically time-out after a 'certain' time interval? If yes, what conditions will cause it to time-out?

Thanks for your time.

[Mark Malone]

I dont think they do timeout once they have formed and everything is stable , i have seen them up for weeks when i check that command , if your unsure you could create a simple ip sla icmp-echo to keep traffic going accross the tunnel to the far end , once the other factors it relies on are stable it would never drop

[andags]

i am seeing "never" in uptime for all dynamic tunnels. Image used in 12.4(15)T7. This is in GNS3 implementation.

The tunnels are up and working fine. Why does it show the uptime as "never"

HUB#sh dmvpn
# Ent Peer NBMA Addr Peer Tunnel Add State UpDn Tm Attrb
----- --------------- --------------- ----- -------- -----
1 14.24.118.1 172.16.0.3 UP never D
1 14.24.119.1 172.16.0.4 UP never D

[Cristian Matei]

Hi,

    That is because you have the tunnels configured manually, via static NHRP bindings (ip nhrp map 172.16.0.3 14.24.118.1), instead of dynamic NHRP bindings done through NHRP messages. Static bindings never expire.

Regards,

Cristian Matei.

[andags]

Yup I remember this one but somehow missed it...Thanks a lot!