Eigrp tunnel not re-establishing after it expired (pppoe)

[jomo frank]

Hello all,

I am using pppoe to connect two locations, the tunnels conneced okay and traffic was  passing until

 the tunnel expires , once this occurs none is  re-establish until I shutdown and restart the physical interface associated  has the dialer , once I do shutdown and no shutdown on the interface after 2 minutes the tunnel is re-established.

Please see attachment with the interfaces and the logs

Regards

[Mark Malone]

Hi
Could you use some basic ip sla to keep the tunnel up so it doesn't go down and take down the neighbor
I have had to do this across modems before when having same issues with vpns

you could always debug ppp packet to confirm if both sides keepalives are getting through they may be dropped and that could be causing the tunnel to drop  

[jomo frank]

Hello Mark,

Could you share the specific ip sla you use to get around the issue so I can included in the config and test same.

Regards

[Mark Malone]

This is just an example put in your own ip address , far end eigrp niegbour or something on the other end a loopback etc it will just keep some interesting traffic going across the tunnel and hopefully should keep it up as it should not time out then

ip sla 100
icmp-echo (FAR END IP) source-interface GigabitEthernet0/0/1
frequency 10

then this starts it

ip sla schedule 100 start-time now life forever


Then check its working with

show ip sla statistics

[jomo frank]

Hello Mark,

This the same as dead peer detection?

Regards

[Mark Malone]

That works specifically with VPN , the ip sla is more of a prob and can be used to keep traffic continually up across a link , minimal amounts , also used to test jitter etc

[jomo frank]

Hello Mark,

I am trying to get a full understanding of the issue, you are saying that the eigrp tunnel expiration is due to  no interesting traffic over the link , hence by implementing the sla the tunnel will be kept up all the time regards of traffic or not.

I notice in your first post you mention you have this issue across a few modems
Is this issue related to the type modem been use but the Telco?
Regards

[Mark Malone · Accepted solution]

Hi
i don't know the full issue of whats exactly causing it you would need to fully debug it to understand whats happening to the keepalive packets between source and destination, pppoe uses them to keep the connection up, if its failing after a certain amount of time it may be because of a number of reasons , the ip sla is just a prob that sends packets from A to B constantly over the tunnel and we have used it before when tunnels were timing out over the internet due to no traffic and dropping off breaking connections , when we used ip sla probes it kept the tunnels up preventing them failing, it could be a quick fix without going through the debugs, and even if it doesn't work it cant break anything as its a probe


If you want to know exactly whats causing the issue you would need to debug both sides as the problem is occurring capture it live and try and see why the connection is breaking down , when it breaks does either side give anything in its local logging to indicate what my eb causing it other than its just dropping ?

[jomo frank]

Hello Mark,

This the same as dead peer detection?

Regards