AP or controller reload causing Windows DHCP BAD_ADDRESS

[MohanKumar30269]

After upgrading Cisco 5520 WLC to 8.10.171.0,  APs are causing DHCP BAD_ADDRESS in Window Server 2008 R2, Server 2012 DHCP servers. Our Current AP Models are AIR-AP2802I-B-K9 and AIR-CAP2702I-A-K9. This is related to Cisco Bug ID: CSCuv61271.

Do we have any fix or workaround for this issue?

Regards,

Mohan Kumar

[MHM Cisco World · Accepted solution]

When a Cisco WLC is rebooted, the AP tries to associate with the Cisco WLC. During this time, the AP keeps renewing the IP address. Every time the AP releases the current DHCP lease, the AP sends out 3 DHCP release packets. This functionality of sending 3 DHCP release packets is common across all Cisco IOS software-based products. Cisco DHCP servers running on various Cisco devices release the IP address when they get the first DHCP release message, but ignore the later messages. However, the Microsoft DHCP server marks the AP as BAD_ADDRESS when it receives the second and the third DHCP release packets.

A workaround for this issue is to configure DHCP release override and set the number of DHCP releases sent by AP to 1, on a Cisco AP or all APs by entering this command:

config ap dhcp release-override enable {cisco-ap | all}

[MohanKumar30269]

Thank you, MHM. I think this should fix our problem, we'll test that get back to you.

[MohanKumar30269]

Thank you, MHM. Your recommendation is solved the problem.

[zachtanksley]

Hello,

Is there a fix or workaround for Catalyst 9800-40 controllers? We experienced a similar issue during a failover.

the config ap commands are not eligible on the new controllers.

[Flavio Miranda]

This can be a bug but dont seems to be the one you mention. The bug you mention reffers to versions:

8.0(110.0) 8.0(115.0) 8.0(120.0) 8.0(122.19) 8.1(102.0)

For the version 8.10 we have a log of bugs but no one related to DHCP.