Solved: DHCP Blocked by VLAN

airiedemann · ‎01-23-2012

We have a server that we remove from the rack. The only role it has is to give out DHCP on the wireless network. I tried enabling the built in DHCP server on the Airespace 4112, though a Catalyst 3750G, but I dont get an address when I'm connected to the wireless network even though the range is enabled. If I set an static IP on my wireless card I can access the network. I also tried enabling DHCP on a Sonicwall that is connected to the Catalyst 3750G.

Do I need to link the DHCP scope to the wireless network?

Is there anything on the switch that would be blocking DCHP since it on a VLAN?

I have the last four ports in a VLAN for the AP's and the internet connection to the Sonciwall.

Thanks fort the help.

cadet alain · ‎01-25-2012

Hi,

go to the interface VLAN where your client are and modify the ip helper-address if necessary.

Regards.

Alain

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sleepyshark · ‎01-23-2012

Did you delete the existing DHCP scopes on the server? Also, what was the old IP of the server? When you re-added it to the network did you use the same IP address? Have you made any other changes to the server/network (particularly network/gateway/routing changes)?

Thanks,

Sean Brown

http://www.sleepyshark.com

airiedemann · ‎01-23-2012

I didnt delete the scope I just unplugged the server so it wouldnt give out DHCP.

I didnt re-add it since I want to use the Airespace built in DHCP server. For now we have the old server plugged in giving out DHCP till I can track down why the only thing that can give out DHCP is the server.

cadet alain · ‎01-23-2012

Hi,

is the DHCP server on a different subnet than the clients? if so have you updated the ip helper-address to point to the new DHCP server? and also does the new DHCP server knows how to get to this subnet( with a static route for example)?

Regards.

Alain

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airiedemann · ‎01-24-2012

Ill check the server but I'm pretty sure that its on the same subent.

Where do I update the ip helper-address?

cadet alain · ‎01-25-2012

Hi,

go to the interface VLAN where your client are and modify the ip helper-address if necessary.

Regards.

Alain

Don't forget to rate helpful posts.

airiedemann · ‎02-10-2012

I ended up using the override DHCP option in the Airespace and pointing the ip to itself.