This sounds like a physical layer problem, as you said.  You refer to
"clients" in the plural sense.  If you have more than one client station,
how are they connected to the router?  Are you using a hub?  

The link light on an ethernet port indicates that the signalling and
carrier required to push frames across the wire are present, sort of like
the carrier detect light on a modem.  If you don't have a link light it
normally means you have a cabling issue.

Linux doesn't seem to do a particularly good job of reporting link-layer
status.  You might try running 'dmesg | grep eth' and 'netstat -i' for
clues, though.  For example, does netstat show any incoming or outgoing
packets on your internal interface?

If you do have connectivity between the machines on the inside and you're
_still_ having trouble you might want to try hardcoding your internal
addresses instead of using DHCP.  Ethereal or tcpdump can also be used to
show what traffic is actually going across the wire.

P.S. You _are_ using private addressing on the inside, as defined in RFC
1918 (http://www.faqs.org/rfcs/rfc1918.html), aren't you?  :)

On Sat, 16 Jun 2001, Chris Mitchell wrote:

> I recently set up my local router using Coyote Linux and am having a problem. I have connectivity 
with the Internet from the router, however when I boot clients to grab an IP it has always failed. 
I have dhcpd listening on the specified NIC (and obviously dhcpcd listening on the other NIC 
connected to the Internet). Obvious questions: Yes, I am using a crossover cable.  Yes, I am 
setting my NIC on my clients to dynamic. No, I am not even getting a link light on the NICs. I 
think this is more of a network problem than a Linux problem, but I didn't want to rule out the 
possibility that maybe I overlooked something on the software front. I'm using 3c509s for both NICs 
and there is no device conflict. I have just realized that I have never got a linklight on the NIC 
dedicated for client connectivity, but I have never got any errors when watching the boot or 
looking at the logs.  I shouldn't have to load the same mod twice for each NIC, should I?
> 
> Chris Mitchell
>