[CentOS-virt] IP aliases from a QEMU/KVM guest
mbaudier at argeo.org
Fri Aug 13 10:47:44 EDT 2010
> On first reading I thought eth1 would have been your second interface
> within the guest, besides eth0. Meanwhile I think you just skipped eth0.
There is a eth0 interface, but it is connected to the internal NAT
network of libvirt.
That way I have a LAN between my guests and eth1 is used for external access.
> That is because you can have just 1 default route. The OVH document does
> not describe a setup for a 2nd interface.
Yes I did have issue with that because the DHCP on eth0 was setting a gateway.
I solved it by forcing:
in eth0 as well.
Here is the ifcfg-eth0:
# Virtio Network Device
> Especially when dealing with more than 1 interface, do NOT set the GATEWAY
> in ifcfg-ethX. By principle always set GATEWAY (in your case
> GATEWAY=x.y.z.254) in /etc/sysconfig/network. Thus you do not need the
ok, good to know, I will fiddle with that.
> If you would have more than 1 interface (the OVH doc does not indicate to
> be written for such a case, neither notes explicitly to give problems in
> that case), then following the OVH doc gives you trouble.
It actually works fine when I had many virtualized interfaces (eth2,
And I actually don't need to add other route-eth2, route-eth3, etc.
(because route-eth0 set the default gateway, isn't it?)
> An aliases interface does not have an own MAC, it is physically the same
> MAC as the primary interface.
maybe that is were I am doing something wrong, because I configured
this virtual MAC within OVH.
> You created a route-eth1:1 file?
yes, I tried that but it did not help.
and as put above it was not necessary for the other virtual interfaces.
> Yes, as said, the security design of the hoster must permit the use of
> defined IPs bound with a dedicated MAC. Ask you hoster.
I will ask them, they are pretty helpful in general.
> You can add additional IPs to virtualized interfaces - either by
good to know that is feasible
Thanks for your help!
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