WiSM information

[rsamuel708]

Could someone discuss the creation and use of the two port-channels you must configure when setting up the WiSM? From the documentation I've read, the port-channels control the two "sides" of the WiSM card with each card being able to support 150 APs. After configuring the port-channels, you have to assign the 8(or 10 in my case) Gig interfaces that are automatically created into these port-channels.

Can someone explain how these gig interfaces are used? Obviously these are logical interfaces, so are they used for backplane communications of some sort for the APs? Do you have to distribute these interfaces evenly across the channels, or can you decide on the ratio based on your needs?

Thanks in advance for any information.

/rls

[jpolczyn · Accepted solution]

I find it useful to look at the WLC-4404. The WiSM is effectively two WLC4404 controllers on a module. The WLC4404 has 4 gbic ports, a service port, and a console port. The service port is a management interface, the four gbic ports are for access points and the controller to communicate.

The WiSM presents the 6500 with 10 gigabit interfaces. You group ports 1 to 4 into one port channel, this port channel connects to the first controller inside the WiSM. You group ports 5-8 into another group channel, these ports connect to the second controller in the WiSM. Port 9 is the service port for controller 1, Port 10 is the service port for controller 2.

With the WiSM, you must create the two port channels. With a WLC4404 it is optional, but honestly I'd be hard pressed to find a reason why you wouldn't set up a port-channel. This port-channel provides a 4 gig link between the backplane of the 6500 and the controllers. When you specify the service-vlan for the WiSM, you're dropping ports 9 and 10 into that vlan.

[rsamuel708]

Great info! Could you explain a little bit more how the service ports are used, and where you specify the service vlan for the WiSM?

[rsamuel708]

Just re-read your post. No need to explain the service ports. I'm assuming the port for mgmt is how you 'session' directly to either controller. Correct?

/rls

[jpolczyn]

Yes, when you issue a:

session slot N proc 1/2

You are basically doing a telnet from the exec shell on the 6500 into the WiSM through the virtual service port. This is why you have to set up a DHCP pool for the service vlan.

[rsamuel708]

Thank you for the information.

/rls