[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] IPV6 and routing



On 10/07/2012 12:10 PM, Gene Czarcinski wrote:
1. Manually configure the IPv6 address/network on the virtualization host. On the default route system, add a static route to the virtualization host. Things will then work.

2. It hurts, don't do it: use a bridge in the virtualization host for IPv6 virtual networks which need to access external systems.

BTW, this is also needed for support of IPv4 routed networks. This can be made a little easier by using 172.16.<nn>.0/24 networks and adding a single static route for 172.16.0.0/16.
Giving this some additional thought, there is a small alternative which offers some advantages: use dhcp "nailed" host ip addresses. while this works for both IPv4 and IPv6, it is more important for IPv6 because all IPv6 virtual networksare "routed."

I have tested this using dnsmasq as the dhcpd6 and dns services provider and there are a number of options for relating a specific host/network-interface and an ip address. In addition to dnsmasq or dhcpd6, you will need to add a static route for that virtual network to the virtualization host on the system which is pointed to by the default route.

There are some documents out there which imply to what I have concluded above but things are left still a little vague. Examples of what is out there are:

http://berrange.com/posts/2009/12/13/routed-subnets-without-nat-for-libvirt-managed-virtual-machines-in-fedora/

http://blog.gadi.cc/routed-subnet-libvirt-kvm/

But, I do not see (or have not found yet) something under http://wiki.libvirt.org

I am not sure where such information belongs but I do believe that it is needed. Examples of where it could be placed are:

http://wiki.libvirt.org/page/VirtualNetworking#Routed_mode_2

http://wiki.libvirt.org/page/Networking

http://libvirt.org/formatnetwork.html#examplesRoute

Gene


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]