On 07/08/2010 05:08 PM, Christopher Chan wrote:
>> Hmmm ... which bond mode are you using?
>
> Why mode 4 of course.
Ouch. Never used that mode.
<snip>
mode=4 (802.3ad)
IEEE 802.3ad Dynamic link aggregation. Creates aggregation groups that
share the same speed and duplex settings. Utilizes all slaves in the
active aggregator according to the 802.3ad specification.
Pre-requisites:
1. Ethtool support in the base drivers for retrieving
the speed and duplex of each slave.
2. A switch that supports IEEE 802.3ad Dynamic link
aggregation.
Most switches will require some type of configuration
to enable 802.3ad mode.
</snip>
So I gather the bonding on the CentOS box is cooperating with the
switches in some non-trivial fashion.
> Too bad there are no defaults that use the subnet assigned to the school
> or the 192.168.0.0/16 (no, not my idea - inherited)
That is a big network. Might make sense in a school though. How many
nodes on it? Any chance a <ahem> staff member plugged an unauthorised
piece of hardware in somewhere.
>> 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?
>
> Hahaha, that was the best part. It just stopped. And stayed that way too
> after a reboot, reboot of switches and only started working again when I
> ran tcpdump for some reason.
tcpdump is probably putting your interface into promiscuous mode which
is triggering something. Perhaps ARP packets.
I think something (perhaps obscure) has changed, you may just not be
aware of it. Comparing your event timeline against your configuration
change management systems may help.
> But another colleague did find this in the iLo report:
You're the only admin but you have a colleague with access to an iLo
report? That puts a big question mark over a previous assertion :-)
> Repaired Network 07/06/2010 12:35 07/06/2010 12:00 2 Network Adapters
> Redundancy Reduced (Slot 10, Port 3)
>
> Repaired Network 07/06/2010 12:35 07/06/2010 12:00 2 Network Adapters
> Redundancy Reduced (Slot 10, Port 4)
>
> Repaired Network 07/06/2010 12:35 07/06/2010 12:00 2 Network Adapters
> Redundancy Reduced (Slot 10, Port 1)
>
> Repaired Network 07/06/2010 12:01 07/06/2010 12:00 1 Network Adapter
> Link Down (Slot 10, Port 2)
>
> Time to ask the HP chap what this is all about.
Looks like the bonding failover process is doing what it should.
A bit more info on you setup might help.
1. What is the purpose of the box with the fat network?
2. are all 4 interfaces being used?
3. are they plugged into the same switch?
4. you've got at least 2 networks, plus 2 vlans, plus a public internet
connection to this box?
K
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