topic Re: DHCP Server issues DOT1X in Network Access Control

DHCP Server issues DOT1X

Jason2005 — Sat, 11 May 2024 17:15:03 GMT

Hello

After I have setted every policy on the switch and everything is working fine through an ISE authentification via dot1x, now server cannot reach its gateway in order to give IP DHCP addresses to the hosts on VLANs!

Can anyone help me please 🙂

Re: DHCP Server issues DOT1X

Mark Elsen — Sun, 12 May 2024 06:36:12 GMT

- Are you talking about an issue on the DHCP server here (or the dhcp-client) ?

Re: DHCP Server issues DOT1X

MHM Cisco World — Sun, 12 May 2024 19:12:03 GMT

If the endpoint not get correct vlan in authz then dhcp not work correctly.

MHM

Re: DHCP Server issues DOT1X

Arne Bier — Sun, 12 May 2024 23:16:33 GMT

NAC doesn't interfere with DHCP. All the usual rule still apply. Not sure what you're asking really. Ensure that NAC authorized endpoints are not getting a dACL that blocks DHCP. And then of course (as usual) ensure that the access switch allows DHCP on the uplinks that go upstream towards the DHCP server.

Re: DHCP Server issues DOT1X

Jason2005 — Mon, 13 May 2024 09:33:58 GMT

no my access switch can ping both ISE but could not ping the server, and they are on the same range!!! whyy??

@Arne Bier

@MHM Cisco World

@Mark Elsen

Re: DHCP Server issues DOT1X

Arne Bier — Mon, 13 May 2024 19:59:01 GMT

When asking a question about why something doesn’t work, how can we possibly answer that question without seeing your config?

If you can't ping the DHCP server that is on the same subnet as ISE, then perhaps it's a Windows device that doesn't respond to ping. Can anything else ping the server?

What have you tried so far?