Client DHCP issue with Cisco 9800-CL WLC

[SHABEEB KUNHIPOCKER]

Hello All,

I am implementing the new Cisco 9800-CL virtual controller for a customer. I am facing a strange issue that the clients in one of the WLANs (PSK) is not getting ip address from DHCP server randomly. I checked the DHCP server for performance issues and all looked good. The controller does not have any SVI in the client VLAN, we are simply utilizing the L2 VLAN and the SVI is on the core switch where the ip-helper address is pointed to the DHCP server. Kindly advise if anyone had faced the same issue.

Thanks

[Thomas Obbekaer Thomsen]

Kind of the same problem here.

For fun we gave the 9800-CL a SVI in the interface , with "ip address dhcp" just to see if it worked "end-to-end".

It does, the 9800-CL gets an IP address on the SVI.

Then the fun starts. Now clients starts to work as well.

Hmmmmmmm .... having an IP address on the SVI is not how it should work, it should just work with L2 right ?

When we remove the SVI , the client will still be able to connect and get an IP address for a while, then it will start failing again.

So Im guessing that the vSwitch eats our BOOTP packets somehow.

I have no idea what to do.

I can just packetcapture on the 9800 and see the client doing its "thing" (BootP) and not get any reply.

Untill I create a SVI in that VLAN where the client is supposed to be "dropped off" .....

Everything on the vSwitch port is set to Accept (like it says in the deployment guide).

If anyone knows how we should proceed, please , we will try anything :-)

/Thomas

[Thomas Obbekaer Thomsen]

PS:

When we remove the SVI, new devices can nolonger get an IP address.

Devices that where connected, can still disconnect and connect.

We dont know for how long this works.

[satdubey]

Check for this bug :- https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvr86358

++ Check if the ip helper addresses on the L3 switch to point to correct Address.

++ Configured a Test open SSID and applied the default policy.

++ Check for DHCP relay where the WLAN gateway resides.

++ 9800 does not support VRF feature.

++ Is the WLAN that you are using in Central Switching or Local Switching?

++ Do you see the Client DHCP request hitting the FTD / firewall Device?

++ Check if dhcprelay statistics increasing

++ What firmware is being used on the 9800?