I have an issue where if the ethernet port on an RB3011 that connects to the main LAN switch is physically disconnected (or the switch is rebooting), the IP address on the router for that interface disappears temporarily, and this cascades through OSPF (undesirably) removing the routes at other sites.

I read that making a bridge was the solution to this as the bridge is always up, and then connect the physical interface (ether3) to it.

1. I have the following working, but wanted to know if that was the best way?

2. There is only ONE port that ever connects to the switch (as a trunk), these are RB3011 routers with switch chip - should I do anything else there?

3. If I set the trunk port ether3 on "/interface bridge port" to only allow VLAN tagged frames, LLDP neighbour discovery stops working on that port - I have to set it to 'admit all' because the LLDP is untagged? I have never experienced this on any other manufacturer - is this the solution?

Thanks in advance

3.