WLC 4402 External DHCP

[cef2lion2]

I have a WLAN on a VLAN. Testing with open security till I get DHCP working. Using external DHCP server. The DHCP server exists on a different subnet then the scope it gives to clients. I have an interface defined on the VLAN and associated with the WLAN. The interface is the subnet of the scope set in the DHCP server. Clients can connect to the WLAN but are not getting an IP address from DHCP server.

Not sure how to make this work when the DHCP server is on another subnet from the clients scope.

Craig

[ericgarnel]

The wlc interface is bound to the vlan and must have an ip that is routable to the gateway address that resides in the same vlan. The dhcp-relay interface needs to be in the same vlan as well (could be the same device if desired)

see http://www.cisco.com/univercd/cc/td/doc/product/software/ssr83/rpc_r/48383.htm#xtocid670622

http://www.cisco.com/en/US/docs/ios/12_1/iproute/command/reference/1rdipadr.html#wp1018606

and here as well

http://www.routergod.com/trinity/

"

[cef2lion2]

Not seeing the issue. Going to regroup and have at it again.

Craig

[dennischolmes]

Check with the server's manufacturer. Some DHCP servers do not like to receive DHCP request by proxy. Your WLC will proxy the request from the virtual interface. This can cause your symptoms.

[cef2lion2]

I will double check with our DHCP group. I thought I asked they about that before and they said yes. They are running Nominum's DCS. Maybe I can see if there log show any hits from our WLC. I assume the request would show up from the interface address I have assigned to that WLAN?

What is odd about this setup is this. The WLC interface is on one private subnet. Client will get private IP on another subnet via the DHCP server. The DHCP server is on yet another public subnet. The network group at main campus say they have DHCP helper setup for these subnets.

Craig

Craig