problem with windows dhcp clients behind dhcrelay

[Sebastian Reitenbach]

Hi,

I have the dhcp server in a separate network, and the clients are in several 
networks, where dhcrelay is listening on some interfaces, and redirecting 
client dhcp requests to the dhcp server.
This works very well with linux clients, usind dhcpcd or dhclient, doesn't 
matter.

When a Linux client requests an IP address, then the dhcrelay includes the 
default-gateway information of the IP address of the interface where it 
received the request from the client, to the server.
However, when I windows XP or 2000 client requests an IP address, I've seen 
with tcpdump, this information is not sent to the dhcp server.

Therefore the dhcp server thinks the request comes in from the wrong 
network, and it says, no free leases, because for this network there is no 
pool configured.

The dhcrelay runs on the router with the following parameters:

/usr/sbin/dhcrelay -a -i eth0 -i eth1 -i ... <DHCP Server IP>

I ran dhcrelay in the foreground, and I also saw the incoming packets from 
the windows clients, and the dhcrelay sent them to the server.

Anyone has an idea what could be my problem?
Any hint would be greatly appreciated.

kind regards
Sebastian