Failed to get DHCP response on interface "Marking interface dirty"

[nh6we]

I am getting the error message above (in message logs) when some of my users try to get an IP address.  During testing, a few devices are able to get an IP address but most are not.

Has anyone seen this error before and how do I correct it.

Thanks any help

[Rasika Nayanajith]

Provide more info like "show sysinfo", "show interface detail " of your WLC & where is the DHCP defined (internal or external)? Are you using interface group ?

You should read below thread as it discuss a similar issue & it may helps you

https://supportforums.cisco.com/thread/2219824

HTH

Rasika

*** Pls rate all useful responses ****

[Sahil Mengi]

What wlc code are you running?

Do you see this in syslog/msglog

"Failed to get DHCP response on interface. Marking interface dirty"?

What does "grep include SIM "show msglog" look like?

Thanks,

Sahil

[nh6we]

Sahil

   I am currently running 7.2.103.0

Thanks

Chris

[Sahil Mengi]

OK, gotta ask one more question, Are you really using interface groups or this error is without those configured?

Plus get the output of "grep include SIm "show msglog"

This could be a known issue.

Thanks

Sahil

[George Stefanick]

Are you the dhcp server is working and handing out leases ?

Sent from Cisco Technical Support iPhone App

[Sandeep Choudhary]

Hi,

I think you will be using interface group. WLC >show interface group detailed

Interface marked with * indicates DHCP dirty interface.

whenever the existing interface goes dirty does the client tries the next available interface for dhcp.

The idea of Interface Groups is that you can have a WLAN utilize multiple interfaces/VLANs/Subnets/DHCP Pools, either for load balancing. At its heart it is purely round robin or based on hash generated using mac address(it depends on the wlc code), but should a client connect in on a certain interface and not be able to complete the DHCP process we mark it as dirty for 30 minutes.  During those 30 minutes we basically remove that Interface from the Interface Group as it won't be selected for use.

follow this thread:

https://supportforums.cisco.com/thread/2219824

Regards

Dont forget to rate helpful posts.

[ivar johansen]

I'm experiencing the same type of issue.

My set up is as follows:

WLC 5508 running 7.4.110.0 no interface group setup, DHCP Proxy set.

External DHCP does receive DHCP requests from WLC and send DHCP Response back, but no DNS update received,

but WLC continues to send requests for same client.

My syslog server receives the following msg. from WLC:

%SIM-4-DHCP_SERVER_NO_REPLY:sim_interface.c: 1307 failed to get response on interface "wlan-internet" Marking interface dirty.

The issue is temporary resolved by sending ping from WLC to the firewall port were the WLAN is terminated.

Regards,

Ivar

[Sahil Mengi]

You guys could be running into this CSCui67640

Clean:Failed to get DHCP response on interface. Marking interface dirty

Open a tac case to verify and get a fix.

Note# Preferably attach wlc port wired trace to the TAC case.

HTH

Sahil