[lug] Re: RedHat LAN comm problem

[George Hyatt]

With help from a friend, the problem is solved.  There were two
problems, really.

I had done a quick RedHat install, providing minimal config data and
accepting the defaults generated by the install tools.  Shouldn't have
done that!  RH inserted a default gateway and a default route using that
gateway.  Since the non-existent gateway was unreachable, RH gave up and
sent the ping traffic onto lo0.  Dave Miller, with tcpdump on his
laptop, diagnosed this right quickly, and we got that fixed.

The machine was now sending ARP requests onto the network properly, but
not seeing the responses.  The machines use an AM79C961A built onto the
board.  RedHat knowledge base had modules.conf params, but these were
for an ISA card.  The lance driver needed to be configured for a
non-standard IRQ.  Dave had /usr/src/linux on the laptop, and a perusal
of lance.c turned up the list of possible IRQs.  We tried 'em until it
worked. (irq=10, dma=5, should you ever run into an ancient NCR with
onboard LANCE.)

In business now.  Thanks for your various suggestions.

George Hyatt