Bridging vlans over T1 link

[Torridon]

Can I bridge multiple vlans over a T1 link? I have 2 1721's, each with 1 serial and 1 ethernet interface. All interfaces are in bridge groups and ethernet interfaces are attached to switch trunk ports, serial ports are ppp links. I'm not having any luck gettting it to work. Any ideas?

[b.hsu]

It is always recommended to enable routing over the WAN link. The reason for this is the quick saturation of WAN bandwidth due to LAN broadcast traffic. To complete your desired configuration, you would need to create an emulated frame-relay link (I have attached documentation below) and create a separate PVC for each VLAN. After doing this, you would configure Integrated Routing and Bridging (IRB) and bridge between the VLAN subinterface on the LAN side, and a dedicated frame-relay pvc-subinterface on the WAN side. I hope this makes some sense.

http://www.cisco.com/warp/public/125/frbacktoback_hybrid.html

[ROBERT WATSON]

You cannot bridge IP with multiple bridge groups over a single serial interface to my knowledge. If your working with IBM or Dec then you have some options with serial tunneling. If you can channelize the t1 and creat multiple serial interfaces based on timeslot then you have a viable solution. Don't waste your time with the frame-relay post as were talking about production environment and real circuits not a lab design.

My SBCUID is rw4549 if you need to call me.

[nemmco]

As previously stated, it is not ideal to bridge over a WAN links but it can be done.

We did something similar when relocating a site with an ATM link. The routers bridged between sites over an ATM link. The switch interfaces connected to the router (bridge) were 802.1Q trunks. You may need to chage MTU size on routers - test with large pings.

We have also used frame-relay encapsulation over a serial link to carry vlans between sites. It does work.

Peter