HSRP not working properly for tunnel interface

Unanswered Question
Jan 2nd, 2008
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Dear all,


When two routers running HSRP that track tunnel interface, configuration as below:


IBSSCC1#sh run int vlan1

Building configuration...


Current configuration : 250 bytes

!

interface Vlan1

description Connection to Customer LAN

ip address 10.122.222.6 255.255.0.0

ip nat inside

ip virtual-reassembly

ip ospf cost 10

standby 1 ip 10.122.222.2

standby 1 priority 110

standby 1 preempt

standby 1 track Tunnel0


There is OSPF configured between both two spoke routers to hub router.


Today during the outage that, OSPF keep flapping on active HSRP router, however, there is no link flapping can be seen, tunnel interface shows up, but the latency is huge when reach to hub router which cause OSPF unstable, since HSRP is track to tunnel0, so it wont trigger HSRP function take place, may i see some advice how to deal with this situation? is that advisable that add keepalive under the tunnel interface?


Thank you,

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s.arunkumar Wed, 01/02/2008 - 21:17
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hi,

Try configuring your tunnel 0 interface with "keepalive" command.This wil make the tunnel interface to behave like physical interface and the tunnel0 will go down when the other end tunnel is down...


arun :)

trinawong Thu, 01/03/2008 - 02:25
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Thanks Arun!


I tried to add keepalive command 'keepalive 9 5', however, once I finished the command, the OSPF dropped after few seconds, the default keepalive is 10 second, I am not sure what is the value is recommended to put that monitor the tunnel interface and not interrupt the ospf as well.


Please advise. thank you.

s.arunkumar Thu, 01/03/2008 - 03:02
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i think the value you configured is ok.

here keepalive packet is send every 9 sec and if it doesnt receive anything within 5 retries then tunnel is set to down.


Do the tunnel is geting down now,or only ospf is droping but tunnel is up??

have you configured on both end of the tunnel ???If not check out that...

guruprasadr Tue, 01/08/2008 - 05:14
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HI,


Best values for Keepalive are:


"keepalive 0 3"


>> Try this.


Do RATE if HELPS


Best Regards,


Guru Prasad R

Pavel Bykov Wed, 01/09/2008 - 00:00
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What is the latency you are seeing on your tunnel interface? What are your timers for OSPF? If your timers for OSPF are very strict, it can think the link is down while it is not. On the other hand, why do you have such high latency on your tunnel interface?


If you set keepalives to 0 as Guru has suggested, your interface will ALWAYS stay up. You can do this on any interface you want turned on without any cables connected.

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