Transparent Bridging

Hey all -

Does Cisco offer anything similar to the functionality offered on a Tasman Networks box that would allow me to bridge VLANs across a serial interface? Basically I'm trying to make a T1 an ethernet segment so that I don't have to deal with routing.

Thanks B

Reply to
bigbrorpi
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Yes.

Any router.

All IIRC??

conf t bridge 1 protocol ieee int xxxxxx bridge-group 1 int yyyyyy bridge-group 1 end

Done.

don't put IP addresses on the interfaces.

For management

loopback 0 bridge-group 1 ip address x.x.x.x

If you have a windows network you may be surprised at the level of brodcast traffic.

Reply to
anybody43

If you have the option, you should STRONGLY consider routing rather than bridging. With "only" a T1, performance will be an issue if the network has more than a handful of users or non-negligable traffic levels or Windows boxes at both sites. The pain you will encounter down the road will make the "ease" of setting up bridging "penny wise and pound/dollar foolish."

Good luck and have fun! And if you choose the path of bridging, you will need much of the former and a warped view of the latter.

Reply to
Vincent C Jones

That of course is the correct answer, please strike mine out. /Bad/ idea unless you do know exactly what you want and understand the implications.

Reply to
anybody43

Greetings,

Vincent is the Guru here, a Bridge between the slow WAN port to a faster Ethernet port is guaranteed to provide serious performance issues on the Ethernet segment. However a couple of years ago I found a "work around" for the performance issues for a LAN to WAN bridge and you may be able to apply something similar to your situation.

In my case, I had an 2600 with 1e & 1s port, and I needed to apply a MAC ACL (7xx numbers) to the Ethernet. Now you cannot apply a MAC ACL to an Ethernet port that is in Routing mode, only when it is in Bridging mode. Also, I had no need for the Ethernet broadcast domain to leave the 2600, so rather than tie the 10Mb Ethernet and the 256Kb Serial together in a bridge, I bridged the Ethernet to a BVI interface and Routed off the BVI. This allowed the Ethernet to support a MAC ACL, and also run at full Ethernet speed. Perhaps something similar could be done here using a BVI with ip unumbered and static interface routes? One possible negative effect is that this would limit your Ethernet broadcast domain, which may be a good or bad thing depending on your specific needs.

Cheers................pk.

Reply to
Peter

~ Hey all - ~ ~ Does Cisco offer anything similar to the functionality offered on a ~ Tasman Networks box that would allow me to bridge VLANs across a serial ~ interface? Basically I'm trying to make a T1 an ethernet segment so ~ that I don't have to deal with routing. ~ ~ Thanks ~ B

Leaving aside questions of performance, wisdom, religion etc ...

You can use Cisco routers to trunk VLANs thru a PPP WAN link. You need an IOS image with what is misleadingly called "BCP Support" (i.e. actually the RFC3518 extensions to BCP.) See

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Feature Navigator
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shows that this is supported on pretty much all IOS router platforms.

Aaron

Reply to
Aaron Leonard

OK - thanks for all of the info. I hear you loud and clear on the broadcasts. What would you guys think of some type of QoS at the switch level to "filter out" the broadcasts or at least drop their priority?

Reply to
bigbrorpi

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