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Community Member

Inter-vlan bridging for sna/netbios

I have a requirement to have several vlans bridged because of sna/netbios applications. I have heard that inter-vlan bridging has the potential for many problems and have heard that running the dec protocol for bridging on the core routers instead of ieee would help in preventing these problems. I do not want the router interfaces to be root. Has anyone done this, and are there any pitfalls?


Community Member

Re: Inter-vlan bridging for sna/netbios

This is from a co-worker, Matthias Binzer:


is the question that the customer wants to bridge into dlsw?

If yes they can use a different bridge-group per interface, thus they do not bridge the vlan's together but only into dlsw.

If you talk about pure transparent bridging i guess the answer is it depends. It depends on your topology and on the other devices paritcipating in the spanning tree. If you dont want the router doing the transparent bridging to become root while you use ieee spanning tree on the router and the switches you can set the bridge priority higher than the default. Thus we would not attempt to become root given that there are other devices with a

better bridge priority.

the usage of dec spanning tree will work as long as there is no other device bridging the same vlan's together. If there is i.e. another router bridging the same vlan's you MUST make sure that this second router also uses dec spanning tree, otherwise you create a loop.

What you essentialy do is to create separate spanning trees overlaying each other.



Community Member

Re: Inter-vlan bridging for sna/netbios

dont want to bridge into dlsw, pure TB. I have 2 core 6k's with MSM's, and 2 links into each floor switch. I am redundant on all ip/ipx vlans but I need to be redundant with the bridged vlans and currently only have one msm bridging on 7 interfaces.

From what you wrote it sounds like I'm on the right track...



Community Member

Re: Inter-vlan bridging for sna/netbios


Perhaps these materials may be beneficial to you:



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