DHCP protocol on WRT54G

It is a mystery to me how the DHCP server works on my WRT54G. If anyone can explain how it works with Windows while not following RFC 2131 I will be indebted to.
I am connecting a system with a proprietary OS using a wired connection. When the computer issues a DHCP DISCOVER packet the router never responds. The router does an ARP for a new address and then adds the address to its routing table using the host name of my computer!  Even it my system now does a DHCP REQUEST using that new address the router still sits there silent. It absolutely never responds to any DHCP requests.
When I use Microsoft Netmonitor, all packets I send are correct. If I watch an XP box get an address thru DHCP I see the same behavior. The router never responds but Windows see's the ARP by the router and assumes that is it's address and does 3 gratuitous ARPs before beginning to use it.
I am completely baffled by this nonstandard behavior. Is there a way to get this router to follow the protocol set forth in the standard - namely - DISCOVER, OFFER, REQUEST, ACK??? 
Solved!
Go to Solution.

It is difficult to tell why the sniffer does not show all packets. You could try a different one like wireshark.
Another reason for this odd behavior could be a second network connection. If the computer has multiple connections to the same LAN (e.g. wired and wireless or two wired) you may see a mix up, e.g. the computer sends the response through a different connection. As you only monitor a single network connection you won't see the packets on the other one.
However, I don't think the computers would use an IP address only based on some ARP requests from the router. That would be highly flawed. Maybe you could test this in some lab environment.

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