On Wed, Jun 27, 2007 at 17:53, Jon Peatfield wrote:

> BTW What make/type of ethernet hardware is this and which kernel modules 
> are being used?  Clutching at straws but can you see any packets from this 
> box when you try to ping (under SL5) from another box using tcpdump?  Does 
> connecting it to a dumb hub change anything?

Jon,

How 'bout that? Your questions got me thinking about hardware, and
here's a distillation of the results:

[root@kappa ~]# lsmod | grep eth
forcedeth              74053  0
[root@kappa ~]# ping -c1 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
From 192.168.1.10 icmp_seq=1 Destination Host Unreachable

--- 192.168.1.1 ping statistics ---
1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms

[root@kappa ~]# modprobe -r forcedeth ; modprobe forcedeth
PCI: Enabling device 0000:00:08.0 (0000 -> 0003)
PCI: Enabling device 0000:00:09.0 (0000 -> 0003)
eth0: no link during initialization.
eth1: no link during initialization.
[root@kappa ~]# ping -c1 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.07 ms

--- 192.168.1.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.071/1.071/1.071/0.000 ms

It's an nVidia nForce NIC:

nVidia Corporation MCP55 Ethernet (rev a3)

At the moment, unloading and reloading the kernel module seems to turn
it on. I'll be chasing the issue further, but for now I expect to be
able to use /etc/rc.local to implement the workaround.

Thanks for your suggestions.

Cheers,
 Pann
-- 
Pann McCuaig <[log in to unmask]>                212-854-8689
Systems Coordinator, Economics Department, Columbia University
Department Computing Resources:
               http://www.columbia.edu/cu/economics/computing/