Cisco WLC's and BlueCat DHCP Leases

[gciarrocchi]

Morning All.

Any guidance would be most appreciative.

2 Cisco 5508 WLC's with about 20 different VLAN /22's shared between them.

We have a Blucat/Adonis DHCP server.

Problem is a user gets a DHCP address in one AP group/VLAN, then get's another one from another APGroup/VLAN. First DHCP address is being retained and not released. So essentially if I have a person with an Iphone walking across all my AP Groups, they are getting a different DHCP address from each one and they aren't releasing as they traverse.

Anyone have any thoughts on this? Is this a DHCP config issue?

Thanks in advance.

[Rasika Nayanajith]

Hi,

This is expected behavior & not an issue. In order to not to break services while client roaming, client should retain its original address (assume it is a voip call & during walk from one place to another, if you have to re-address, call will break)

Not only two ap groups, even if you have two different controllers in L3 seperated, client will remain its original IP from 1st WLC (called anchor) & 2nd controller (foreign) will tunnel back traffic to 1st controller.

That's why you should not assign different subnets floor wise, or building wise, if you expect users to roam around without dropping its connection. Have a bigger IP subnet  instead of break it down

HTH

Rasika

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[gciarrocchi · Accepted solution]

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DHCP was not releasing IP's correctly.

Checked with BlueCat and was able to force "One Lease per client"