FortiAP DHCP Option 138

Forum|Forum|15 years ago
October 14, 2010
6 replies
8512 views

Hi ! Yesterday my four FortiAP 220A arrived and I am very happy with them. Bye-Bye Trapeze ;-) I have to use DHCP option 138 because the wireless controller is located on another subnet. Using the DHCP server of a Fortinet test box is working very well but using a Windows 2000 DHCP doesn' t work in any way. I added option 138 in every possible way but it' s not working. Does anybody has a clue for me what I have to configure or maybe experienced the same problem ? Citylight

rwpatterson

New Member

Perhaps you need a DHCP relay on the FGT interface? This will allow one subnet to get to the DHCP server on another subnet, like your option ' 138' .

CitylightAuthor

New Member

Thanks for your fast reply but unfortunately we have a DHCP server in every subnet. Using a relay would cause a lot of fun for the UHD :-) I opened a ticket at Fortinet and wait what will happen. Citylight

rwpatterson

New Member

So the subnet your are in has a server, and you want to force some units to go to a different subnet/server?

CitylightAuthor

New Member

I' ve got the wireless controller in the network 172.16.0.0/16. The FortiAP is at the network 172.18.16.0/20. There is a DHCP server at each subnet. The FortiAP has to find the wireless controller by DHCP because broadcast and multicast doesn' t work. It is working well if I use a Fortnet as DHCP server but it' s not working if I use a Windows 2000 DHCP server but I have to (Windows network). Citylight

rwpatterson

New Member

Does the FortiAP not need a 172.18.16.0/20 address? Is there no Windows server there? I still don' t see how this is an issue... If the Windows server on 172.16.0.0/16 has the DHCP scope for 172.18.16.0/20, just tell the FGT interface to send requests for 172.18.16.0/20 to the DHCP server on 172.16.0.0/16. That' s it.

CitylightAuthor

New Member

Yes, the FortiAP gets an address at 172.18.16.0/20 from the Win 2000 DHCP server. There are two different DHCP servers, one at 172.18.16.0 and one at 172.16.0.0. The networks are connected bye a Foundry MG-8 as a router. To tell the FortiAP that the wireless controller is located at 172.16.0.0 I need option 138. I tried another DHCP server (Turbo DHCP) and it is working too. I guess there is a problem with the Win 2000. Citylight