[Openstack-operators] Networking breaks in CentOS guests but works with Ubuntu guests

Joe Topjian joe.topjian at cybera.ca
Wed Apr 3 19:30:00 UTC 2013


Hi Lorin,

Does this happen shortly after the guests were created? Or usually a few
hours/days later? If the latter, are these guests seeing large amounts of
bandwidth?

Thanks,
Joe


On Wed, Apr 3, 2013 at 1:16 PM, Lorin Hochstein <lorin at nimbisservices.com>wrote:

> Hi all:
>
> I'm having a strange issue where networking on my CentOS guests isn't
> working properly, but things are working fine with my Ubuntu guests.
>
> I'm running Folsom on Ubuntu 12.04, nova-network, not multi-host.
>
> The first symptom is that CentOS instances don't get IP addresses via
> DHCP. If I trace the DHCP requests and replies using tcpdump, I can see the
> reply from dnsmasq reach the vnetX interface of the compute host, but it
> doesn't get to the eth0 interface of the compute host. (I'm at a loss here
> about how to debug something like that).
>
> If I try to statically configure an IP address on the guest instead,
> networking still doesn't work. I can't ping anything on the subnet, and I
> don't even see the icmp traffic on vnetX of the host.
>
> I've tried this twiddling the following options, but no change in behavior:
>
> * Adding the following rule to nova-network node: iptables -A POSTROUTING
> -t mangle -p udp --dport bootpc -j CHECKSUM --checksum-fill
> * Adding the same rule to nova-compute node
> * Setting libvirt_use_virtio_for_bridge to "yes" and "no" (restarting
> nova-compute, re-launching instances)
> * With and without vhost_net loaded in nova-compute (restarting
> nova-compute, re-launching instances)
> * Disabling iIpv6 inside of the CentOS guest
>
> Has anybody encountered this before?
>
> Lorin
>
> --
> Lorin Hochstein
> Lead Architect - Cloud Services
> Nimbis Services, Inc.
> www.nimbisservices.com
>
> _______________________________________________
> OpenStack-operators mailing list
> OpenStack-operators at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>
>


-- 
Joe Topjian
Systems Administrator
Cybera Inc.

www.cybera.ca

Cybera is a not-for-profit organization that works to spur and support
innovation, for the economic benefit of Alberta, through the use
of cyberinfrastructure.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-operators/attachments/20130403/b0216080/attachment.html>


More information about the OpenStack-operators mailing list