Hello Folks!

I have a router that sits a bit bad between two CRS switches with a lot of end user devices have it as default gateway and other that is not capable of multiple default gateways, ospf, rip etc. pure end user devices. The CRS switches is not capable doing MRSTP in the chip, they are to old.

I need some redundancy for the router between the two switches. As for now the router has become isolated a couple of times and loss of connectivity.

I tried to create a bridge between the two switches inside the router, yet I had RSTP on the bridge it resulted in a packet storm in both situations with and without vlans.

The router interface has VLAN trunk with 20-30 vlans attached to it.

Question, can I bond the two router interfaces using active backup and vlan trunks or is that a bad idea ?

There's VRRP that is used to backup RBs with same configuration, I don't know if it's your case, try configure it and see what happens.

Hello Folks!

I have now tested active backup bonding with vlans, works perfect.
A vlan trunk with at least 10 vlans operates perfect, if the active interface fails, the active backup takes over within seconds during heavy load.