Bridge with Redundancy

[crumpet75]

Hi,

Can anyone point me to reading material on setting up a bridge with redundant connections.

I can connect to a remote location via wireless, homeplug, and possibly ethernet over coax with DLink's DXN-221. Wireless seems to be the fastest, but sometimes goes down for short periods. The homeplug devices work more consistently, but in my building they are slow. I suspect the DLink DXN-221 would be best, but it is not available yet and is expensive. To improve the bridge's connection, I was wondering if I could setup a bridge that uses 2 or more of the available connections? So when the wireless connection briefly goes down, the homeplug device would keep the connection up (although slowly until the wireless came back up.)

I suspect some people use a similar bridging concept when connecting remote offices. If you have 2 or more internet connections from different service providers, you could have devices on each end that decide how to route the traffic between each site across the different internet connections and reassemble on arrival at the destination. If a link goes down, then one of the other connections is likely still up.

Does anyone here have experience with a redundant bridge like this? And if so, do you know of a DIY bridge like this with some linux boxes?

Thanks

 

[networker]

You can do that on OSI Layer 2 with Spanning Tree. Put a spanning tree capable switch on both side of your links. If one links fails, spanning tree opens the 2nd link. On Layer 2 you can also configure link aggregation.

An other option is routing on Layer 3.

Mirko

 

[crumpet75]

Link Aggregation

I just learned about Link Aggregation and I think it is what I am looking for.
http://en.wikipedia.org/wiki/Link_aggregation

I am going to read up on this more and see if I can use link aggregation for multiple bridges to improve up time and bandwidth.

Bridge 1: HomePlug
Bridge 2: Wireless Connection
Bridge 3: Possibly Ethernet over Coax when it becomes available.

I loose my connection to frequently with a wireless bridge... and the HomePlug is not fast enough... So I am wondering if pairing both together with link aggregation will be a possible solution. It may be expensive... but it seems like it may work since I can't lay a real cat5 cable between the two locations.