I just confirmed that using dummy interfaces with a real netmask does actually make things work the way I want. I notice the lo /32 interface still gets created with the same IP. Are there any drawbacks in doing it this way? Gordan Gordan Bobic wrote: > Adrian Reyer wrote: >> Hi Gordon, >> >> On Thu, Oct 14, 2010 at 10:22:15PM +0100, Gordan Bobic wrote: >>> Is there a way to add a static route to a VM on loopback? >> >> You don't need to. As the guest has no network, it doens't need to >> route, either. The kernel has the network and does the routing. >> Do you experience any problems with this setup? > > Yes I am seeing a problem with this setup. > > Host A: > lo:192.168.0.1/32 > eth0: 192.168.1.1/24 > > Host B: > lo:192.168.0.2/32 > eth0: 192.168.1.2/24 > > When host A connects to 192.168.0.2, the connection looks like it came > from 192.168.1.1, rather than 192.168.0.1. I don't want my app on host B > binding on listening on 192.168.1.0/24 interface. I want the connection > to be going via the internal loopback only. I also want to keep the > iptables rules relatively sane and intuitive. > > Normally, this would be implicit by the network scope, but since lo is > different and setting 192.168.0.1/24 on it would make the local host > respond on the entire range, I need an alternative solution that would > work more sensibly. Would using a dummy network device work for this? Or > is there a better way? > > Gordan