Etherchannel with Cisco 1562 wireless Bridges

[rruiz19]

I am deploying another pair of 1562D to create a redundant wireless connection to the remote building and also achieve aggregate throughput.  The 1562 are lightweight that connect to a 5520 WLC.  The WLC is running code 8.10.181.0 and the 1562's are connected to layer 2 switches.  The main building L2 switch is a 3850-48P and the remote L2 switch is a 9200-48P.  I wanted to create an Etherchannel to connect both wireless bridge links.  The current wireless bridge is setup for VLAN support and I'm trunking 3 VLANS across the bridge.  I just want to verify I'm not missing anything here that I should be aware of or if I'm missing anything obvious that I should enable on the WLC.  I've attached a drawing to provide a visual.  Thank you for the time.

[balaji.bandi]

Technically possible if the Links connection are same speed.

In case not worked as expected, other Option you can have Trunk with Prirority on STP port and fail over option or  if Layer 3 you can use any IGP to Load balance.

AP should be WGB mode.

[rruiz19]

I'm going to try this solution this weekend. I'll let you know if I have any issues with this.

[Scott Fella]

@balaji.bandi is on point.  I had customers in the past with non-cisco redundant bridges and used priority on STP.  I only had a few that setup the ports as L3 so they can decide what traffic goes over which link.  Either one should work for you.

[balaji.bandi]

Sure, let us know the outcome.

@Scott Fella Cheers !

[rruiz19 · Accepted solution]

So I try to implement the solution this past weekend and a couple of issues came up.

• In our envirionment, we setup our interfaces when part of an etherchannel/channel-group to mode active.  It seems LACP doesn't like the bridges because it would come up for a bit but then it would go into a suspend state.  I then changed the channel-group to mode on.  The etherchannel came up and I thought I was good to go.
• My colleague then mentioned what happens if one of the pair radios goes down (primary bridge is down) but the physical interface are up to the AP's, will the traffic go into a black hole.  So we tested this and unfortunately this was true.  So technically this can be done but if either of the wireless bridges goes down from a radio perspective, there will be some form of outage in the L2 setup I originally mentioned. 

In the end, I didn't go forward with my design because it didn't really give us a great advantage.  I hope this helps others and thank you all for your input.

[Rich R]

FYI: Cisco have deferred 8.10.181.0 so it's unsupported by TAC now - think about upgrading to 8.10.183.0 asap.