DHCP with Multiple VLANs

[m-niemi]

AP's -> approx. 20 AP1100 with 12.2(15)XR2 working fine (with thee vlans).

After about 8 months we bought some more 1100 AP's and the problems begun with new AP's. With one management vlan(native) and one vlan with EAP(PEAP) everything is ok. If I add one VLAN for public acces/open authen, clients are not getting IP address from dhcp for that vlan.

First two vlans have dhcp server behind router helper address, the third one has a dedicated server.

Tried with 12.3(2)JA and the problem is the same. I saw that this is not new problem here, but i begun to wonder could it possibly be hardware problem with new AP's?

Mika Niemi

Network Manager

University of Art and Design Helsinki

[dixho]

12.3(2)JA certainly does not work because of bug CSCsa44872. I do not know why it does not work with 12.2(15)XR2. You probably need to open a TAC service request.

[gwcrook]

I do not believe it is a hardware issue. Our AP1200's were purchased over a two year period and we have the same issue. We upgraded our ap's to XR2 and then had to downgrade to 12.2(15)JA for them to allow client to receive DHCP. I have read posts saying XR2 works and I have read posts saying XR2 does not work. Our environment uses multiple vlans and ssids with DHCP servers on different subnets. I have configured an ap with 12.2(15)JA and tested it with clients and it works, then upgraded to XR2 and the clients do not receive an IP, then downgraded to 12.2(15)JA and the clients receive an IP. We currently have 60 AP's deployed with another 70 scheduled for deployment in May 05. The latest advice from TAC was to upgrade to 12.3(2)JA2 but we have not tested it. We use PEAP and mac-authentication with the microsoft supplicant on both SP1 and SP2.

[GENE MCTIERNAN]

I am having the same difficulty, and I did not see the 12.2(15)JA on the download site, do you have a source for it?

Thanks,

Gene

[GENE MCTIERNAN]

Never mind, looked further down :-)

Thanks,

Gene

[o-ziltener]

From my point, software 12.3(2)JA2 does still not forward broadcast between the interfaces.

Oliver

[fernando]

Well, I'm using 12 AP 1200 and all them works fine. I'm using 12.3(2)JA and the client request for a IP address sending a broadcast to the network, and the AP forward this to the Ethernet, in 8 different VLANs. I dont think it's a IOS problem.

[kevin_miller]

It's obvious from the number of posts about this issue in the discussion forums - there is a serious problem with DHCP over wireless. Cisco has obviously not resolved it. I'm having a similar issue with 12.3(4)JA to my WLSM. I share your frustration.

[ccsmith705]

I also have ver. 12.3.(4)JA and I am experiencing the same problem. Do I understand that the only solution at this time is to downgrade to 12.3(2)JA or 12.2(15)JA to get DHCP to work with multiple vlans?

[d.beaver]

I would love to hear from you once you have tested 12.3(2)JA2 to see if it is successful. I have a production network that I cannot make those kind of changes to, but would also love to upgrade to a newer version of code that works with DHCP. Thanks for doing all of the leg work as you have described above. It looks as though you are closer to solving the problem than TAC is...

I look forward to hearing more.

[kevin_miller]

I've had some success recently on this. By removing the "mobility trust" statement from the tunnel interface, users are now able to get an IP consistently. This, of course, stops static IPs from working - but it is ok for my current configuration. I'm still fighting with the time it takes for clients to get and renew IPs - but that is another issue. At least it eventually works. Good Luck!

[ccsmith705]

Unfortunately I am not using a WLSM ( I assume that is what you are referring to when you said that you removed the “mobility trust” from the tunnel interface.) I upgraded to the latest IOS ver. 12.3.7.JA and that did not fix my DHCP problem. Looks like I’m going to have to downgrade!

[Ahmed Elnagar]

Hello;

anyone find a solution for this issue???