Having an issue with the 9800 controller setup in sso, where I cant get clients to get a dhcp reply. The aps are up.. the ssid are up.. but external dhcp not so much
I have tried setting it up globally under policy without effect. I have tried setting up the svi with an helper and I can reach the dhcp server . but traffic comes back on the mgmt intf (ap intf) been looking everywhere for some good guides on the 9800 regarding dhcp externally (also the vrf options) does anyone have any good tips here=?
Do you see any logs
follow below gude
It would be really useful if someone could give a quick breakdown on the difference between AireOS config and IOS XE ....not getting anywhere fast with the documentation. Thanks.
I'm also having an issue with a new 9800-L not passing DHCP requests properly. I'm sure it's a config issue. On AireOS the relay/proxy setup was all in the interface settings. You could have it source DHCP requests or ignore and send the requests through the connected switch, which is what I do.
In the 9800, it looks like the general policy screen has a DHCP text box, but that does nothing. I've also tried adding SVIs on the 9800 and put in helpers there just to see if it would work and it does not. A client debug shows a broadcast DHCP request going out, but nothing coming back. Trunks look good and an AireOS WLC connected to the same switch with the same VLANs is sending DHCP requests fine.
I am in the same situation on a new 9800 deployment. I tried several configuration, just like kdavison suggests. I did some packet captures on the L3 router and the WLC is clearly not relaying the DHCP request. We had to enable DHCP relay on the L3 router instead. It was working fine with a previous AireOS controller in the same subnet.
DHCP relay however works when using an internal DHCP pool on the 9800 and relaying to the Loopback of the 9800.
We are running version 16.12.1s.
My problem is that the DHCP Request of the client never makes it out of the controller because I cannot not see any UDP/67 while capturing packet at the L3 router (actually a firewall). Sure you can have issues with option 82 but this is a different matter here.
I will try and replicate the issue on the lab, maybe I missed something on the customer configuration...