WLC Dropping DHCP Discover Packets

Question

Hello
I have following setup:
[Notebook]----wired connection----[Cisco Lynksys wlan ethernet bridge] )))))) wirelessConnection (((((  [AP]-----[switch]-----[Router]-----[WLC]
I use a seperat DHCP Server. so on the WLC the DHCP Proxy is disabled.
what i know is - the WLC should receive and forrward he DHCP Discover to the layer3 interface on the router, where the ip-Helper is configured. From there it should go to the DHCP Server.
BUT - here comes the problem -
The WLC Dropps the DHCP Discover.
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP received op BOOTREQUEST (1) (len 308,vlan 253, port 13, encap 0xec03)
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP option len (including the magic cookie) 72
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP option: message type = DHCP DISCOVER
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP option: 61 (len 7) - skipping
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP option: hostname = Test (len 4)
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP option: vendor class id = MSFT 5.0 (len 8)
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP option: 55 (len 13) - skipping
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP options end, len 72, actual 64
*DHCP Socket Task: May 05 16:06:26.153: 88:ae:1d:b7:b7:c2 DHCP dropping packet (no mscb) found - (giaddr 0.0.0.0, pktInfo->srcPort 68, op: 'BOOTREQUEST')
Can anyone tell me why this happens?

Answer 1

HI Chris,
First enable DHCP Proxy on WLC.
(Cisco Controller) >config dhcp proxy enable
and make sure that For DHCP proxy to work, a primary DHCP server must be configured on each controller interface that requires DHCP services.
To kow more about DHCO on WLC:
http://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/110865-dhcp-wlc.html#Internal-DHCP
Regards
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