[Linux-cluster] OT? Odd Xen network issue

[Madison Kelly]

Rick Stevens wrote:
> Madison Kelly wrote:
>> Hi all,
>>
>>   I hope this isn't too off-topic being more a Xen than cluster 
>> experience, but I am having trouble with the Xen mailing list and I 
>> gather many here use Xen. If it is too off-topic, the please have a 
>> mod delete it and kick my butt. :)
>>
>> I've got a simple two-node cluster, each with three NICs running 
>> CentOS 5.3 x86_64. Each node has this configuration:
>>
>> eth0 - Internal network and VM back channel (IPMI on this NIC)
>> eth1 - DRBD link
>> eth2 - Internet-facing NIC, dom0 has no IP
>>
>>   I've built a simple VM that uses 'xenbr0' and 'xenbr2' as the VM's 
>> 'eth0' and 'eth1', respectively. I've set a static, public IP to 
>> domU's eth1 (xenbr2) but I can't ping it from a workstation nor can 
>> the domU ping out. I know that the network itself (outside the server) 
>> is setup right as I tested the static IP from that cable earlier on a 
>> test machine.
>>
>>   Could someone hit me with a clue-stick as to what I might be doing 
>> wrong? Let me know if any logs or config files are helpful.
> 
> First, see if you can ping dom0's NICs?  If not, that's the first thing 
> to address.
> 
> Next, are the domUs NICs up? ("ifconfig -a" will tell you).  If not,
> bring them up.  Remember, you might have a fight if the domUs use
> Gnome's NetworkManager.  Make sure it's disabled and that you have the
> classic configuration set up in the domUs correctly.
> 
> Verify that first, and we'll move on from there.  You might also want
> to have a look at this:
> 
>     http://wiki.xensource.com/xenwiki/XenNetworking
> 
> It might help explain things a bit or give you some other ideas.

Thanks for the reply, Rick!

I ran tcpdump on dom0 against the VM's vifU.1, against xenbr0 and even 
against vif0.2. In all cases I could see by ping requests, but as soon 
as I ran it against peth2 I'd get nothing. Turns out that the D-Link NIC 
had issues with 64bit that I somehow missed when I first built and 
tested the servers. New Intel NICs sorted it out right away.

Madi