topic WLC2504 clients not receiving DHCP leases in Wireless

WLC2504 clients not receiving DHCP leases

sp0000003 — Sun, 04 Jul 2021 08:14:29 GMT

I'm stock with a 2504 using version 7.0.220.0 that won't lease out DHCP adresses

Wifi clients are unable to get a DHCP lease from an external DHCP server.

The WLC are handling 3 WLAN, 2 using internal DHCP server, 1 (that wont work) using external DHCP. The external DHCP server, is a router/firewall (out of my reach) that suffered from a power out, a short while ago, ever since the DHCP is not working on that VLAN, if client are getting static ip adresses, everything works fine. If i'm using the same network link, and plug it into a computer, I get a DHCP address.

I've enable DHCP proxy

Debbuging DHCP, using: Debug DHCP packets enable

Gives me this:

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP received op BOOTREQUEST (1) (len 308,vlan 20, port 1, encap 0xec00)

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP option len (including the magic cookie) 72

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP option: message type = DHCP INFORM

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP option: 61 (len 7) - skipping

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP option: 12 (len 1) - skipping

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP option: vendor class id = MSFT 5.0 (len 😎

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP option: 55 (len 13) - skipping

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP options end, len 72, actual 64

*DHCP Socket Task: Nov 08 14:21:11.397: c8:0a:a9:cc:6d:f6 DHCP dropping packet (no mscb) found - (giaddr 0.0.0.0, pktInfo->srcPort 68, op: 'BOOTREQUEST')

Thanks

Re: WLC2504 clients not receiving DHCP leases

Sandeep Choudhary — Mon, 11 Nov 2013 10:29:51 GMT

Hi Steen,

When a client is in DHCP REQ state on the controller, the controller drops DHCP inform packets. The client will not go into a RUN state on the controller (this is required for the client to pass traffic) until it receives a DHCP discover packet from the client. DHCP inform packets are forwarded by the controller when DHCP proxy is disabled.

Please check this, if still u r facing issue then provide more info.

Can you please paste a client debug of the client having DHCP issues.

Go to cli of the wlc and run the client debug . Diconnect the client then reconnect and gather the output and post.

Regards

WLC2504 clients not receiving DHCP leases

sp0000003 — Tue, 12 Nov 2013 08:07:53 GMT

This solved the issue.

Thank you so much...

Hi,

laukik.nahar1 — Mon, 05 Jun 2017 18:53:49 GMT

Hi,

Can you explain how did you resolved the problem, because i'm facing the same issue.

Thanks.

I believe the issue was that

Rich Quinlan — Mon, 05 Jun 2017 20:02:00 GMT

I believe the issue was that the setting for DHCP proxy was enabled, and disabling it resolved his issues.