how do assign different subnets to same dynamic interface and inturn to same SSID

[vinodjad1234]

Hi  .,

I am bit confused to configure the 2 different subnets into same dynamic interface in cisco wireless controller .

my requrirement is existing subnets is excausted and and new subnet is there however not able to understand , how do i configure secondary in same interface ...

Can anybody please do suggest me on this ?

[Rasika Nayanajith]

You can do this using a feature called "interface group" or "vlan select". Refer this post for more detail

http://mrncciew.com/2013/01/27/understanding-vlan-select-feature/

Above post is based on 7.0.116.0 code, if your WLC code is different refer the config guide for configuration syntax, still concept remain same

HTH

Rasika

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[vinodjad1234]

Hi Rasika,

I have come across your name many times .... cool ...you are like inspiration for others in wireless

i understood the interface group scenario however my requirement is different ...

I will be not creating different vlan for new subnet .... I need to map new subnet to existing one which is already configured on controller. something like secondary ip address ...

Can i configure it on controller ?

[Rasika Nayanajith · Accepted solution]

Hi Vinod,

Thanks for the kind remarks :)

If you already configured an dynamic interface for a WLAN, you cannot assign another subnet without creating an interface group.

Alternatively, you can create an AP group, which can map to new dynamic interface & assign several APs (like a building or two) to that AP group & map new dynamic interface to the WLAN under AP group.

I think first option is more scalable & you can add further subnets as requirements comes in futures. 

HTH

Rasika

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[George Stefanick]

My 2 cents .. If you plan to keep the same interface -- I would just expand the existing interface and call it done. Normally vlan select / interface groups is more for creating smaller subnet sizes. 

[Rasika Nayanajith]

How far you will expand George? We have gone up to /21 (2048 host per subnet) & then do interface grouping to map 3 subnets of that size to a given SSID

Rasika

[George Stefanick]

This was a topic of discussion many times. At what point is large to large of a subnet. 

I spoke to many in the know people at Cisco and what I've been told is the limitation is the upstream router / switch. 

In fact I was told the stadiums are all in one subnet. They turn off milticast. 

Our design is class B subnets. This was a network I took over.  I was looking at interface groups this is what started the conversation. 

[vinodjad1234]

Hi All ,

Good to see very information discussion ... Thanks to all ...

[Philip91]

You mean something like secondary IP Address as you can do it on a Layer3 SVI ?

-- No you can´t

As I understand you need two subnets in one vlan ?

Just disable DHCP Proxy on your Dynamic Interface. As you do this WLC acts as Layer2 extension for that Subnet and you can deal with ever mechanism you want on your Layer3 Switch. Don´t care about Ip on Dynamic Interface in that case. It will have no effect on your setup anymore.

Correct me guys if i´m wrong

Greetings

Philip

[JordieFike]

Did you create a whole new set of IPs? If you were on say 10.200.24.xxx with subnet 255.255.255.0, wouldn't you just "open up your current set of IPs" by having it be 10.200.24.xxx-10.200.25.xxx with a subnet of 255.255.254.0? Or 10.200.xxx.xxx to 10.201.xxx.xxx with a subnet of 255.254.0.0?