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Cisco WLC DHCP upgrade issues

Hi,

I've discovered an issue with our WLC 4400 series controllers when we do firmware upgrades (recently moved to 6.0.199) it seems to reset the dhcp server on the controller but the Access points still retain their old IP until the lease runs out (48hrs). This means that any AP's requesting a new lease often get an IP conflict for the first 48hrs after the upgrade and we experienced areas where AP's wouldnt connect.

Is this a common issue and is there anyway to get the AP's to request a new address from the controller?

thanks,

Matt

1 REPLY
Cisco Employee

Re: Cisco WLC DHCP upgrade issues

Hi Matt,

When you do a WLC upgrade, a WLC reboot is required, this results in the DHCP lease table getting restarted as well.

Solution:


1-Setup an external DHCP Server to overcome this.

2- Restart the access points, so they request a new IP address.

This is mentioned on WLC release notes 6.0.199.0 that you are running, it is for clients, for the rule still applies:

Link

http://www.cisco.com/en/US/docs/wireless/controller/release/notes/crn6_0_199.html#wp581125

Internal DHCP Server

When clients use the controller's internal DHCP server, IP addresses are  not preserved across reboots. As a result, multiple clients can be  assigned the same IP address. To resolve any IP address conflicts,  clients must release their existing IP address and request a new one.

The same also applies on newer releases such as 6.0.199.4 and 7.0.

Have a good day.

Serge

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