[NTLUG:Discuss] Troubleshooting a network connection - fixed

[LEROY TENNISON]

As usual I stumbled across the solution quite by accident (or maybe it was divine help).  Noticed that the MAC address seemed different under Knoppix which led to the discovery that CentOS had selected opposite NICs for eth0 and eth1 from what Red Hat 9 used.  This may be due to my starting out with only one NIC originally under RH9 and then adding the second later, it's been too long to remember.  What I did was put
 
 HWADDR= ...
 
 in both ifcfg-eth0 and ifcfg-eth1 (both in /etc/sysconfig/network-scripts, this path will be different for other distros such as SuSE).
 
 This raises a couple of questions:
 
 How does Linux decide which NIC is going to be eth0, eth1, and so on?
 
 How do I tell what driver is being used for eth0 and eth1.  'ifconfig' gives me the hardware address and IP configuration but doesn't tell me what driver.
 
 Anyone know where the format of ifcfg-eth0, ifcfg-eth1 and so on is documented?
 
 Thanks for the help.