Can't see ADSL modem

[Marko Vojinovic]

On Thursday 02 February 2012 00:55:31 Timothy Murphy wrote:
> I have a small mystery on my home network.
> The machines on the network all run Fedora-16 or CentOS.
> All the machines except one, running CentOS-6.2,
> can ping the ADSL modem at 192.168.1.254 .
> 
> The CentOS-6.2 machine does not get any response to pings
> from the modem, but is able to ping sites beyond the modem.
> 
> Could some knowledgeable soul suggest a reason for this?

Are you sure the problem is with the CentOS machine and not the router itself? 
You can try to exchange the ports for that CentOS and one Fedora machine 
(reconnect the cables at the router side), and ping again from both machines. 
If CentOS works and Fedora doesn't, the problem is with the router. I've seen 
routers do these things --- one of the ports behaves differently or has reduced 
functionality or otherwise...

OTOH, if CentOS still doesn't work, then it's most probably the firewall --- 
either the CentOS firewall or the router firewall. Check them both for dropping 
ICMP packets.

I cannot think of any other problem. Can CentOS ping other machines on your 
LAN?

HTH, :-)
Marko