I have a network running HP 3500YL switches with multiple class C vlans. They connect back to corporate headquaters through a 6509 router. They switches are properly configured with helper addresses for DHCP. The DHCP servers in corporate are Windows 2003 server based DHCP server. Here's the strange thing. I can plug a laptop into a port on one of the switches on a particular vlan and it gets a DHCP address without any problems. If I plug WIDS device that is setup for DHCP it will not get an address. Same port same switch same vlan. If I set a static IP on the WIDS device it can connect back to HQ. We ran a sniffer and determined the WIDS device sends out the DHCP broadcast. It gets through the 6509 to the DHCP server. The DHCP server replies with an address but the packet seems to stop at the 6509 without ever getting to the device. The laptop makes the request without any problems.
Thanks for the help!