[CentOS] Networking just stopped working

Thu Jul 8 01:26:20 UTC 2010
Kahlil Hodgson <kahlil.hodgson at dealmax.com.au>

On 06/07/10 22:48, Les Mikesell wrote:
> Chan Chung Hang Christopher wrote:
>> Christopher Chan wrote:
>>> And now the thing is working again...
>> It's not working again.
>> Running tcpdump -i vlan seems to trigger something to get the network 
>> working again but as soon as I stop tcpdump...nada, zip, zilch.

If you have two machines on the same network with the same IP address
you get behaviour like this.  Had this happen once when an engineer
reset a UPSs and it took on the IP address of a main switch.
arpwatch is your friend.