Network issues

Network issues

[Shaun R.]

I have a weird problem when deploying new hosts.  If i boot a host on a 
normal kernel, then install xen and reboot it and then deploy DomU's for 
some reason eth0 aliases dont work on the DomU's.  The primary ip (main ip 
of the eth0 interface) works fine but for some reason aliases dont work 
until you arping -s <eth0:alias_IP> 0.0.0.0 and then they only work for a 
short time (until arp times out).  The only solution i've found to resolving 
this is too hard reboot the host, and then after that everything works as it 
should.  Anybody else seen anything like this?

~Shaun 

Re: Network issues

[Mark Williamson]

That's interesting.  Some clarification seems in order so we can understand 
exactly what your problem is.

On Monday 21 July 2008, Shaun R. wrote:
> I have a weird problem when deploying new hosts.  If i boot a host on a
> normal kernel, then install xen and reboot it and then deploy DomU's for
> some reason eth0 aliases dont work on the DomU's.  The primary ip (main ip
> of the eth0 interface) works fine but for some reason aliases dont work
> until you arping -s <eth0:alias_IP> 0.0.0.0 and then they only work for a
> short time (until arp times out).  The only solution i've found to
> resolving this is too hard reboot the host, and then after that everything
> works as it should.  Anybody else seen anything like this?

OK.  So if I'm reading you right, what you're saying is that you see:

1. boot with normal kernel (networking enabled)
2. reboot into Xen kernel (networking enabled)
3. start domUs
4. IP aliases don't work properly in domUs
5. power cycle the host
6. boot into Xen kernel (networking enabled)
7. IP aliases *do* work properly in domUs?

Is that correct?  Sounds like a fairly weird problem but networks are good at 
creating those :-)

Cheers,
Mark

-- 
Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/)

Re: Network issues

[Shaun R.]

> OK.  So if I'm reading you right, what you're saying is that you see:
>
> 1. boot with normal kernel (networking enabled)
> 2. reboot into Xen kernel (networking enabled)
> 3. start domUs
> 4. IP aliases don't work properly in domUs
> 5. power cycle the host
> 6. boot into Xen kernel (networking enabled)
> 7. IP aliases *do* work properly in domUs?

Yep, thats what's happening.  I cant say if it's a issue on the network end 
or if it has somthing to do with Xen.  There are over 300 regular servers on 
this network though and none of them have this problem, course they are not 
running Xen.  I figured it was a problem with the old xen version i was 
running (3.0.4) but now i just packaged/deployed newer versions of Xen on 
hosts and still seeing the problem.  It's weird that it doesnt affect the 
primary ip of the DomU, but only the aliases.

~Shaun