Any issues with 2 layer 2 paths between endpoints???

[Terence Lockette]

Hello,

I want to ask a question which may have a simple answer that I'm either forgetting or just didn't realize.  My question is, are there any potential issues with having two layer 2 paths between endpoints?  Here is the scenario: we purchased a building where we'll have a 1G layer 2 link between this building and our main office.  The folks moving to this office currently have connectivity via a pair of Ubiquiti wireless bridges that provide a total aggregate throughput of approx. 1.5Gbps.  Once the staff moves to the new location, we will want to move the Ubiquiti link to the new building and use it as a redundant path in the event the 1G layer 2 link fails.  The configuration will allow for traffic to take either the physical link or the wireless link since both are layer 2 and will allow the necessary VLANs to traverse them.

I cannot recall for the life of me, if there are issues with this type of configuration.  Spanning-tree comes to mind but I don't think the Ubiquiti bridges participate in STP and only specific VLANs will be allowed over any trunk links to cut down on broadcast traffic.  Any thoughts on this?  Could there be any gotcha's I need to consider or anything I may not have considered?  I'll be happy to answer any questions or provide any additional details I may have left out.

Thanks,

Terence

[Philip D'Ath]

I would probably use spanning tree everywhere, and let spanning tree hold one link down.

Depending on your kit, you could also use LACP and say that you only want one circuit active at a time (which would make the other a standby).  This approach also avoids spanning tree and loops.

Depending on your kit you could also use a FlexLink with the "switchport backup" command, and specify one interface to be a backup to the other.

[Terence Lockette]

Philip,

Thanks for your response.  I'll test out these suggestions and will decide on which I'm going to implement.  I'll rate the response once I confirm which is going to work for me.

Thanks!