topic Re: Cisco 5508 and Interface Groups in Wireless

Cisco 5508 and Interface Groups

bm_5789 — Mon, 05 Jul 2021 14:57:08 GMT

Looking for advice/suggestions for the following:

I am creating a new SSID and will have more than 500 devices connecting. The dhcp scope is a /23 network so I know ip space will run out. Can I create an interface group and assign 2 interfaces each with a /23 network? Will it alleviate my problem of not enough ip addresses? TIA

Re: Cisco 5508 and Interface Groups

Veera Bhaskar Mutyala — Fri, 08 Dec 2017 18:47:55 GMT

yes i see thats one best workaround and there is another possibility of secondary subnet on that vlan..

Re: Cisco 5508 and Interface Groups

bm_5789 — Fri, 08 Dec 2017 16:05:22 GMT

I appreciate your response but I'm not exactly sure what you mean.

Re: Cisco 5508 and Interface Groups

Rich Uline — Fri, 08 Dec 2017 16:25:26 GMT

I think Veera is talking about the secondary IP address command under the SVI. For example:

int vlan 10
  ip add 10.0.10.1 255.255.255.0
  ip add 10.0.11.1 255.255.255.0 secondary

The problem with a secondary address is it's incompatible with DHCP because all DHCP discovers are relayed using the primary address as the source. It's fine if you want to manually assign all the secondary hosts, though.

Re: Cisco 5508 and Interface Groups

Veera Bhaskar Mutyala — Fri, 08 Dec 2017 16:44:42 GMT

Thanks Rich, and yes 'interface grouping on WLC' is perhaps the best option on the controller based scenario but there is another workaround where you can always extend IP;s on a vlan by adding secondary subnet, here is a discussion related to it

https://supportforums.cisco.com/t5/lan-switching-and-routing/secondary-ip-address-and-dhcp/td-p/1836681

Re: Cisco 5508 and Interface Groups

bm_5789 — Fri, 08 Dec 2017 17:59:22 GMT

So I will perform the following:

* Create the interface group

* Assign the new SSID to the interface group

* Devices will acquire an ip address from either dhcp scope. Not sure how that will work.

Does that sound right?

Re: Cisco 5508 and Interface Groups

Veera Bhaskar Mutyala — Fri, 08 Dec 2017 19:15:20 GMT

provided you have the individual interfaces crated already,

you should be doing--->controller--->interface groups--->Add Group--->Interface group name & Description--->Add

then go to interface group you just created and add the individual interfaces to be grouped under this group

then go to WLAN-> select interface group(usually have (G))at the end of its name-->APply

so you are applying the interface group to WLAN/SSID or AP group

I have seen this working for me and also i believe this does dhcp balancing to pick leases out on both subnets,,,,

go thru this link:

https://rscciew.wordpress.com/2014/01/22/configure-dynamic-interface-on-wlc/