[noob] direct routing with only one routable ip?

[Sam Tran]

On 12/13/06, Jed Reynolds <lists at benrey.is-a-geek.net> wrote:
> I've read the MiniHowto and the UltraMonkey Tutorial. Something that I'm
> not entirely clear on if I can do a direct routing setup with only using
> one routable IP address (aka, the VIP).
>
> What I would like to do is to put the realservers on a DMZ with
> non-routable addresses. And since I have two nics on the realservers,
> can I configure the realserver nics plugged into the WAN switch with the
> VIP? (arp_ignore of course). And  then I wouldn't need to do a lo:0,
> would I ?
>
> Like so:
>
> WAN: x.200.200.112/28
> VIP: x.200.200.113
> DIP: 10.0.0.2
> RIP eth0: 10.0.0.3
> RIP eth1: x.200.200.113
>
>
> Or do I have to have a routable IP for each of the realserver eth1
> interfaces?
>
> All the direct routing examples that show two nics have routable IPs on
> them. The other DR examples have all been on non-routable networks.
>

In LVS/DR topology, the real servers need to be in the same physical
segment (LAN) as the director. If your VIP is a routable IP and your
real servers are in a private subnet, your only option is LVS/NAT.

Sam