DHCP issues after implementing MST

[jonathanrklein]

We have an A5500 as our core router and A5120s as our access switches in a collapsed core environment.

We use Bridge Aggregation for our uplinks and have the vlans on the aggregation link.

We also have DHCP relay on our core pointing to the appropriate DHCP server.

As far as the MSTP topology, the core router is the primary switch with stp root protection enabled on the links to the access switches. BPDU protection is enabled on the access switches.

DHCP snooping is enabled on the the switches with trust enabled on the uplinks and DHCP server link.

However, some ports on the access switches in the network are not getting DHCP. Am I missing any commands? Could it be the switch or the link to the dhcp server?

Please help.

Jonathan

[darylwan]

You can verify if MST is a problem by setting a client to static IP, if this client is able to ping to DHCP server via the 5500 core, then network path/MST is not the issue.

> However, some ports on the access switches in the network are not getting DHCP

Are you saying that clients on some ports on the same switch are able to grab DHCP?

If yes, I would think it's a DHCP server issue.

Daryl