[CentOS] Networking just stopped working

Thu Jul 8 06:19:12 UTC 2010
Kahlil Hodgson <kahlil.hodgson at dealmax.com.au>

On 08/07/10 15:41, Christopher Chan wrote:
> No new boxes. Not possible for any other box to be assigned the same
> ip internally via dhcp and definitely not the same Internet ip.

Exactly.  DHCP server would check for a conflict before assigning an
address and is definitely not the source of the problem.

> Perhaps you care to explain why BOTH vlan interfaces stopped working?
> The odd chance that two other boxes each took one of the other ip
> address?

Did not know that both had stopped. Conflicting IP addresses was just a
suggestion.  May not be the problem at all.  With bonding, breaking one
might break both down at the MAC level ...

Hmmm ... which bond mode are you using?

> The box with the problem just so happens to be the only box using 
> bonding, 802.1q and a four port Qlogic Netxen NIC. I think the
> chances of there being a problem between these three more likely than
> some 'ghost' boxes getting assigned the same ip addresses when I am
> the only admin around.

If you are the only admin, then its not that likely.  Then again, I once
had a power spike reset a wireless router on my network without me
knowing.  Default settings were close by not quite right, and it took me
a couple of days to track down the problem :-(

If it was working, then suddenly stops, then something must have
changed.  I gather you have some configuration and change management
system in place?  Backups of conf files?