topic WLC - 4402/4 - Vlan Interface Addressing in Wireless

WLC - 4402/4 - Vlan Interface Addressing

Rick Meier — Sun, 04 Jul 2021 01:02:09 GMT

I currently have 7 WLCs with the same Vlan interfaces defined across all 7 controllers. Does anyone know the best practice for addressing these interfaces on each of the WLCs. I currently have each unique Vlan interface assigned with the same IP address across all 7 WLCs. This is working. Should I leave it this way or should I assign each controller with a different address for the Vlan interface?

Re: WLC - 4402/4 - Vlan Interface Addressing

dancampb — Fri, 11 Sep 2009 13:16:48 GMT

If I read this correctly you have used the same IP address on all the VLAN interfaces across all the controllers? If so I'm surprised this is working. Each controller should have a unique IP address for every interface. The only interface that should have the same IP address as the other controllers is the virtual interface.

Re: WLC - 4402/4 - Vlan Interface Addressing

Rick Meier — Fri, 11 Sep 2009 13:47:43 GMT

These interfaces are the interfaces that are assigned to the SSIDs. In the manual they are called the Dynamic interfaces. I inherited the network and the addresses were assigned when I got here. It's been working this way for close to a year. The section on the interface config page entitled "Interface Address" with the fields Vlan identifer, IP address,netmask and gateway. Is what I'm talking about.

Re: WLC - 4402/4 - Vlan Interface Addressing

dancampb — Fri, 11 Sep 2009 14:05:00 GMT

Yes, the dynamic interface on a controller has to have a unique IP address.

Re: WLC - 4402/4 - Vlan Interface Addressing

Rick Meier — Fri, 11 Sep 2009 14:08:46 GMT

Thanks for your help. I'll change them.

How was it working w/ them being the same? What kind of problems do you think this would have caused?

Re: WLC - 4402/4 - Vlan Interface Addressing

ehlers.kevin — Fri, 11 Sep 2009 21:43:43 GMT

The controllers, assuming you have it configured as such, act as dhcp relay agents. Presumably, if the router got the wrong mac address in its arp entry, the dhcp message would be lost.

Clients could have taken a while before getting a dhcp addr (race condition for router arp entry) and not been able to work if dhcp was required.

That said, I've seen the controllers work with the dhcp server set to 255.255.255.255 so the ip helper addresses on the routers would pick up the requests.

Re: WLC - 4402/4 - Vlan Interface Addressing

George Stefanick — Sat, 12 Sep 2009 15:48:14 GMT

dan --- always there to help! 5 stars