LAG on wireless controller

[suthomas1]

Hi,

We have two wireless controllers to be connected to two Core switches ( active/standby ). What is the best way to connect the controllers to the switch,

should there be 2 physical connections from controller A to Core Switch A & similarly for Controller B to Core Switch B?

Also do we do need to enable LAG on the controllers for this?

Please advise on this. Thanks in advance.

[Rasika Nayanajith · Accepted solution]

If you want to enable LAG then all ports needs to connect to same physical switch (unless your two core switches are pair of 6500 in  VSS mode).

If no lag enable then you can connect WLC ports to two different switches. Then traffic will go via one physical port unless you configure different port as primary for certain vlans.

My preference is enabling LAG & giving lager bandwidth to WLC with simple configuration.

HTH

Rasika

**** Pls rate all useful responses ****

[Scott Fella]

I too agree using LAG. There is only a small percentage when I don't use LAG, but it's for a work around.

Check this link

http://www.cisco.com/en/US/docs/wireless/controller/7.2/configuration/guide/cg_ports_interfaces.html#wp1277652

Sent from Cisco Technical Support iPhone App

[Leo Laohoo]

I use LAG.

[suthomas1]

Thank you all.

So it means , two ports each from the WLC01 will be connected to Core switch01 and same for WLC02 to Core Switch02.

&  both the ports on core switch side should be on one port channel. eg. Po120 for both ports on Core switch 01 with LAG enabled on the wlc.

i hope my understanding is correct, please do comment.

[Rasika Nayanajith]

Yes, that is correct.

What is the WLC model ? Does it have only two 1G uplink ports ? If it has more than 2 I would aggregate all of them.

thanks for rating as well

HTH

Rasika

[suthomas1]

Thanks. It is 5508.

[Rasika Nayanajith]

Then go for 8G as long as you have 8x1G switchports on your switch. That's max throughput you can get from a single 5508.

HTH

Rasika

[devils_advocate]

Are your 6500's running a first hop redundancy protocol such as HSRP??

If so, is spanning tree enabled and blocking the redundant links between the access switches and the 6500's?

You won't want to connect all or some of the 1Gb ports on the 5508 to just the active switch otherwise you have no redundancy.

I believe on the WLC you can't have multiple LAG groups which means its all or nothing in terms of etherchannel which may cause an issue if everything is plugged into the Active switch and this fails.