We are experiencing recents issues where clients (MS Win 7 PCs) are not 'taking' the IP address being given to them via DHCP. Our routers are configured with 'ip helper-addresses' that point to DHCP servers. I ran 'debug ip udp' and 'debug ip dhcp server packet detail' and it shows the client requesting an IP address, the router forwarding the request to the DHCP servers, the router getting the reply back from the DHCP server and then forwarding the reply back to the client. The clients never gives any indication it receives the IP address. The client continues to show the default 169.x.x.x IP address and continues to issue bootp's requesting an IP address.
I did notice in a debug that the client prepends 01 to its MAC address when it issues a bootp request. When the router replies back to the client it does NOT include the 01. Is this an issue? The destination MAC address field is 48 bits so this 01 realy part of the MAC address? Other devices that connect to this device work fine when requesting an IP address via DHCP. I do not think they prepend 01 to their request though.
Here is the debug
003935: Mar 11 09:39:25.938 EDT: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=308
003936: Mar 11 09:39:25.938 EDT: DHCPD: client's VPN is usps.
003937: Mar 11 09:39:25.942 EDT: DHCPD: setting giaddr to x.x.x.x.
003938: Mar 11 09:39:25.942 EDT: UDP: sent src=x.x.x.x(67), dst=x.x.x.x(67), length=308
003939: Mar 11 09:39:25.942 EDT: DHCPD: BOOTREQUEST from 0188.51fb.6621.9c forwarded to x.x.x.x. (Here is the client prepending 01)
003940: Mar 11 09:39:25.942 EDT: UDP: sent src=x.x.x.x(67), dst=x.x.x.x(67), length=308
003941: Mar 11 09:39:25.942 EDT: DHCPD: BOOTREQUEST from 0188.51fb.6621.9c forwarded to x.x.x.x.
003942: Mar 11 09:39:26.038 EDT: UDP: rcvd src=x.x.x.x(67), dst=x.x.x.x(67), length=317
003943: Mar 11 09:39:26.038 EDT: DHCPD: client's VPN is .
003944: Mar 11 09:39:26.038 EDT: DHCPD: forwarding BOOTREPLY to client 8851.fb66.219c. (Here is the router sending the reply to the MAC address without 01).
