I have issues across two 4500 switches interconnected by pry and backup link.
The Pry(prymary) link is a Lan eXtension
The Backup link has additional swithces in between performing Q-in-Q(L2TP)
on the two 4500 switches pry and Backup links interfaces are configured as TRUNKs
If the two interfaces are up at the same time we experience FLAPPING %C4K_EBM-4-HOSTFLAPPING: However if either one the prymary or the backup link is UP at a time everything is fine but there will not be auto link failover.
How can i have both links up and have Auto failover in this L2 enviroment ?
I have used spanning-tree cost and priority and does not help.