[libvirt-users] How to add static routes?

[Nils Toedtmann]

Hello

i have several libvirt hosts (CentOS6, kvm), each with an internal
libvirt "default" network with "forward mode='route'". I have two
questions concerning static routes.

To give some context: On each of my libvirt hosts there is a VM acting
as a OpenVPN-gateway to the other libvirt hosts.



[A] How can i add a persistant static route on the libvirt host to one
of its guests?

Someone had already asked this on this list in 2011 but apperently did
not receive an answer [1]. Likewise, i found that a
/etc/sysconfig/network-scripts/route-virbr0 does not get applied when
libvirt starts its default network.



[B] How can i make libvirt's dnsmasq push static routes into the guests?

Apperently dnsmasq supports pushing of static routes using DHCP options
33 or 121 [2], e.g. "--dhcp-option=121,x.x.x.x/yy,z.z.z.z". But i did
not find how to add that to a libvirt network declaration.

I know that if i had [A] working, the host could redirect the IP traffic
on behalf of the guests, but i'd like to avoid the resulting extra hop
and the flood of ICMP redirects.



Please advise.  Cheers  /nils.



[1]
https://www.redhat.com/archives/libvirt-users/2011-December/msg00061.html
[2] http://tools.ietf.org/html/rfc3442