Hello,

I'm building my new virtual infrastructure.
My physical servers are hosted in datacenter with one public ip address.
So I configured my vm (domU) to use nat.

On one server I can connect to every vm hosted in this server and vm can connect to each other.
But I need one vm on server A can connect to another vm on server B.

I think there is a lot of iptable rules to enable that but how can I do that ?

Is someone know another way ?


Thanks

your domU uses nat? should be dom0, right?
if you have enabled dom0 masquerading / nat, you should put the domU's in the same subnet (e. g. 192.168.0.0/24), and you should be fine. iptables has a forwarding chain that is responsible for filtering that kind of traffic.

oh, you are searching for DNAT with iptables. works, but your concept sucks.

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Ok, if my concept sucks what is your solution ?
So I've installed OpenVPN in both physical servers, the first is the server and the other one the client and the next servers as well.
I have set 1 virtual sub net for server 1 and a other one for the second (10.1.1.0 and 10.2.1.0 respectively).
Vpn works well, from server 2 I can ping a virtual machine of server A , but I can't ping a virtual machine of server B from server A (the vpn server)


This is the output of server A (vpn server)
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.1.10.1 * 255.255.255.255 UH 0 0 0 vif8.0
10.1.8.1 * 255.255.255.255 UH 0 0 0 vif7.0
10.1.2.1 * 255.255.255.255 UH 0 0 0 vif12.0
10.8.0.2 * 255.255.255.255 UH 0 0 0 tun0
10.1.9.1 * 255.255.255.255 UH 0 0 0 vif9.0
10.1.1.2 * 255.255.255.255 UH 0 0 0 vif3.0
10.1.3.1 * 255.255.255.255 UH 0 0 0 vif6.0
10.1.1.1 * 255.255.255.255 UH 0 0 0 vif4.0
10.1.5.1 * 255.255.255.255 UH 0 0 0 vif5.0
xxxxxxxxxxx * 255.255.255.0 U 0 0 0 eth0
10.2.1.0 10.8.0.2 255.255.255.0 UG 0 0 0 tun0
10.8.0.0 10.8.0.2 255.255.255.0 UG 0 0 0 tun0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0

And route table of server B (vpn client)
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.8.0.5 * 255.255.255.255 UH 0 0 0 tun0
10.2.2.2 * 255.255.255.255 UH 0 0 0 vif6.0
10.2.1.3 * 255.255.255.255 UH 0 0 0 vif2.0
10.2.1.4 * 255.255.255.255 UH 0 0 0 vif4.0
xxxxxxxxxxx * 255.255.255.0 U 0 0 0 eth0
10.8.0.0 10.8.0.5 255.255.255.0 UG 0 0 0 tun0
10.1.1.0 10.8.0.5 255.255.255.0 UG 0 0 0 tun0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0

(I'm using xen network mode)
Is someone has an idea of what's wrong on my setup

you should get a bunch of public ip addresses on both sides, you really want to.

Finally, I made it work.

I setup a VPN (openVPN) connection between my physical server and pushed the the virtual network from each other like it was real hosts.

So now I can connect from a vm on server A to vm on server B and so on.

I have other problems that I will post in a new post

resolved