Cisco ISE Dynamic Vlan assignment and DHCP Reservation

[babai]

Hi All

Had anyone experienced any issues with Cisco ISE Dynamic Vlan Assignment when the PC have DHCP Reservation on a Microsoft DHCP Server.

In my lab it seems that Vlan is assigned on the Cisco switch port by ISE but the supplicant doesnt receive any IP.

Any ideas would be appreciated.

[Ben Walters]

Are you able to see the DHCP request reaching the server?

Is the DHCP server on the same layer 2 as the VLAN that is assigned to the workstation or do you have the correct IP helper in place on the gateway?

Have you tried manually setting the switch port to that VLAN and connecting the computer without the ISE VLAN assignment?

[babai]

Hi Ben

Yes. The helpers are in place and the device receives an ip when manually configured with the access vlan. But when dynamically assigned then its getting an 169 address

[Ben Walters · Accepted solution]

What does your switch port configuration look like? Do you have portfast enabled? 

It sounds like the DHCP might be failing before the port is put into the correct VLAN, if you leave the client connected for 5-10 minutes does it eventually get an IP address?  (I think 5 min is the time before windows will try to request a new IP address.) 

[babai]

Thanks Ben. I have now identified the cause of the timeout. Thanks for pointing in the right direction. 

Regards