Wireless User cannot get IP Address

[Gilang.Ramadhan]

Hi, 

I have issue with the wireless users are not getting IP address from the IOS DHCP server.

But, after ipconfig /renew the wireless users get IP address. LAN user can get IP Address without problem.

the setup of the network is straight forward🙂

WLC-->CORE-->DIST-->AP-->User

the DHCP scope has been created on the core.

I am using WLC 5520 8.10.142.0

Thanks,

Gilang

[balaji.bandi]

this suggests that you need to check the lease time of the client. it may be sutck with DHCP.

[Gilang.Ramadhan]

this is the dhcp pool configuration in Core for wireless,

ip dhcp pool 38
network 10.42.38.0 255.255.254.0
default-router 10.42.39.254
dns-server 10.41.21.21 10.41.21.20 10.42.21.20
domain-name mapin.local

I have tried configure the lease time 1 day, but the results are still the same,

when wireless user connect to SSID after the lease time is over, the problem appears.

[balaji.bandi]

if you have enough pool increase the lease time

[JPavonM]

You are maybe hitting CSCvw30043.

The solution is to upgrade to latest suggested version (8.10.151.0)

As this is due to APs not forwarding DHCP offers, if you need a temporary workaround before scheduling the migration then increase the DHCP lease to 10 days so the client do not start asking to validate lease after 50% of the lease time has gone, and also to disable session timeout for the WLAN or configure it for 15-20 hours to prevent re-authentication on business hours.

HTH
-Jesus
*** Please Rate Helpful Responses ***

[Rich R]

Probably not your problem but the only time I've had Windows users not able to renew IP addresses was when IT accidentally deployed a Windows firewall policy update which blocked unicast DHCP packets causing Windows to fail DHCP renew.

[Leo Laohoo]

Reboot the AP.  

If the reboot works then it is CSCvw30043 as what @JPavonM said.

[saravlak · Accepted solution]

Enable dhcp-required on WLAN's advanced config -This should force the client to do dhcp whenever it connects/roams, there could be slight delay and not noticed in data network. Don't apply this change on WLAN using voice/video services.