WLC question

gavin han · ‎12-27-2010

Hi,

I need to use one WLC and need to have use APs on each of 8 floors. we don't want to span vlans on each floor. so we do this with WLC. how to config it without spanning the vlan to AP and to WLC. sorry, i'm new to this area.

ehlers.kevin · ‎12-27-2010

You're not really spanning a vlan to each floor with this method, but rather tunneling everything back to the controller. The controller then dumps the clients off onto a vlan. So the vlan only exists between the controller and whatever it plugs into.

However, I'm not really sure what your needs are, but here are some solutions to what you want to do:

1) If you need to keep clients in their own vlan per floor, you can use AP Groups. When setting up AP Groups, you setup a wlan->interface mapping. You then add the APs to the ap group.

We generally use one or two vlans (up to 2048 clients per subnet/vlan) on each of our controllers. The controllers and clients don't seem to have a problem with that.

This would be the best solution if you're in an enterprise environment.

2) You could also use H-REAP and locally switch the vlan. You'd need to supply a 802.1q trunk to the APs. That way the traffic would stay local to the floor instead of being tunneled back to the controller. It's a little trickier to manage the H-REAP APs, but it could be a better solution for you.

Use this one if each floor is a separate customer and/or department and they want to maintain control/firewalling of their own equipment.

HTH

gavin han · ‎12-28-2010

Option 1 would be best option to go for. Thanks.

I've few questions if you can help me:

1. since each floor will have its own vlan, so we will have saperate AP group for each floor? and saperate interface for each floor?

2. to map the interace - we have to specify VLAN indentifier for each interface, but VLAN of each floor won't be spanned to the WLC. how to take care of this?

3. what should be the config. of the switch interface to which WLC connects to.

Thanks..

ehlers.kevin · ‎12-28-2010

1. since each floor will have its own vlan, so we will have saperate 
AP group for each floor? and saperate interface for each floor?

Yes. You'll need both a separate group and interface for each floor.

2.
 to map the interace - we have to specify VLAN indentifier for each 
interface, but VLAN of each floor won't be spanned to the WLC. how to 
take care of this?

Do you want the wireless clients to be on the same vlan as the rest of the machines on the floor? In that case, you'll need to do H-REAP and locally switch the clients. The controllers tunnel all client traffic back to the controller. Wherever the controller plugs in, you'll need some number of vlans there.

You really don't need to do this. You can have a single pool (or more, whatever) of addresses and have all wireless clients use the same address space. Think of the client<->AP<->WLC connection like plugging into a switch. It's transparent to the clients. They'll end up wherever the WLC puts them.

 3. what should be the config. of the switch interface to which WLC connects to.

It should be a trunk. It should have all the vlans you want on it.

-Kevin

gavin han · ‎12-28-2010

Thanks Kevin. but as per our requirement. we need to have saperate vlan hence saperate subnet on each floor.

so as you said, best option would be H-REAP?

you said "wherever controller plugs in, you'll need some number of vlans there". I didn't follow this statement(this doesn't mean we will have to span vlans, right?).

pls advise. Thanks.

ehlers.kevin · ‎12-29-2010

Thanks Kevin. but as per our requirement. we need to have saperate vlan hence saperate subnet on each floor.

so as you said, best option would be H-REAP?

Yes. The other option is spanning your vlans to the switch where your WLC connects. I assume you have some firewalling requirements. In the H-REAP case, it makes it a lot easier to enforce because the wireless clients are treated the same as the wired clients.

you
 said "wherever controller plugs in, you'll need some number of vlans 
there". I didn't follow this statement(this doesn't mean we will have to
 span vlans, right?).

Yes. Either 1) span your vlans or 2) create a second set of vlans/subnets for each floor. I.e. a wired and a wireless vlan/subnet per floor. => a total of 16 vlans for 8 floors.

-Kevin

gavin han · ‎01-05-2011

so by going for H-REAP for each floor. will we have seamless roaming? I meant to say, will there be an interuption when client moves between floors?

we want seemless roaming and there shouldn't be an interuption.

weterry · ‎01-05-2011

I have not fully read the details in the posts above this, but if you want Layer3 roaming then you can't do HREAP with unique vlans between the floors. This is exactly where Central Swtiching (Local Mode AP) and AP Groups comes in to play.

You really need to make sure the vlan/subnet for each floor can be trunked in to the WLC, make an interface for each vlan/subnet, and then make an AP Group for each floor mapping a wlan to the subsequent vlan....