09-25-2007 05:53 PM - edited 03-03-2019 06:55 PM
Hi, I have quite a large VTI network with three headends. At times the spokes start to flap one or two of their tunnels to the headends and this continues until I manually shut down the interface and bring it back up.
Is there a way I can automate this procedure? I was thinking about IP Event Dampening but this does not shut the interface down so the issue will continue. I was also thinking about an EEM applet but am not too experienced with EEM and my attempts so far have not resolved the issue.
Does anyone have any suggestions?
10-03-2007 06:13 AM
Try to lower the MTU of the GRE tunnel from 1436 to 1400 on both sides
10-03-2007 06:21 AM
Do you get any useful messages with the flap?
Kevin Dorrell
Luxembourg
10-03-2007 02:48 PM
Hi, thanks for the replies.
In regards to the GRE comment, I should have mentioned earlier we are using VTI. Also, I do not think it would be an MTU issue as the issue occurs rarely (about twice a week, most times it is a different site) and we have over 130 sites setup. It is not a massive issue but it would be good if we could fix it.
And nope, no useful error messages. It just says the interface goes down then it comes up a few seconds later then goes down & continues to flap in that fashion until someone manually shuts the interface down and brings it back up.
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