NiftyClusters Mitch wrote:
Good list: Also add multiple runs of "traceroute" and also try ping, ping -f , ping -A and ping -R. See also ping6 If routes are dynamic we have one answer to the problem, I would expect traceroute to have 'one' answer on a simple net. If packets are falling on the floor then we need to know why.
The different invocations of ping can tell you if packets drop at slow or fast transfer rates. ping -R is slightly different than traceroute but if the return routes flip one way then the other we should know why.
Watch out for /etc/sysconfig/network-scripts/ifcfg* where hardware addresses, subnet masks, device driver links/ names etc. no longer match the hardware when things move.
More, watch out for /etc/sysconfig/networking/devices where configs that you thought you deleted live on to get you when your run system-config-network. I just could not figure out, for a while, why when I deleted /etc/sysconfig/network-scripts/ifcfg-eth1.bak it would be right back there!
Consider snooping packets on the link to see if all is as you expect. I keep an old, slow network hub (not a switching hub) for the times when I want to see the bits on the wire and not the bits that the local driver is able to show me.
I have one as well. It is so hard to find them anymore....