Ivan Pepelnjak wrote:
Classic IOS (I did not test XE, XR or NX) can handle inbound updates with AS path lengths above 255, but fails miserably when it has to send an oversized update (producing invalid BGP UPDATE message), resulting in a flapping BGP session (anyone who wants to test this behavior and report/fix this bug can get all the files needed to reproduce it).
Just to reconfirm. The issue arrives with sending an update, not receiving? So if an ISP does not have a limit and their IOS cannot handle this, they will send an invalid BGP UPDATE to the downstream peers causing them to reset regardless of their max as-path settings? Just trying to reconfirm, so I can inform my customers if there was anything they could do to prevent it, or if it is actually their provider that instigated the peer reset by sending invalid updates. -Jack