I have two sites which are connected via eBGP to a provider. These links are the main connection to the headquarter.
For backup purpose we use a transparent L2 link between both sites; where an iBGB neighbor ship is setup.
In case of a failure of one of the main links the traffic of the affected site should go through the iBGP neighbor and it's eBBP partner on the other site.
This works - but the fallback (when the failed router comes back) doesn't work.
Then the routing gets asymmetric.
The problem is to worsen the iBGP routes against the one from the provider.
Tried to local pref, AS path prepend etc. - but nothing works.
Isn't there a simple solution?
Thanks for your help