Port Forwarding and NAT: I give up :-(

Hello to all! I’m new to VPS and Cloudmin. I have tryed now for days to do the below tasks, but I have no idea how to set it up correctly. Anyone could help me with a step by step tutorial.

Using a Server4You dedicated server I need to have Cloudmin setup based on KVM and CentOS 6.5. The server has one public IP Address. The virtual servers should be accessible using port forwarding (e.g. machine should be reached using with ssh using “ssh -2205 mypublicip” or its website on port 80 or 8080, etc). I bought a second public IP address to assig it to a second virtual server for Zimbra access.

Here is what I want to achieve using the Cloudmin interface:

  1. Add a new virtual machine with an IP Address picked automatically from the range (lets say …
  2. Access port 22 on the virtual machine like described above
  3. Access the virtual machine from the host
  4. Access another virtual machine from the virtual machine (e.g. from, especially for SSH

Here a message from S4Y support:

Please be aware they are all next-hop routed meaning they will require a 32-bit netmask (CIDR - /32, dotted decimal - and because of those two things, have no gateway. They would be configured as virtual IP addresses on the NIC.

Please also be aware bridged networking does not work here, for VMs, but a routed or NAT configuration will.
The abstract overview of using a VM with a routed or NAT’ed configuration is the host OS is configured with the AddOn IPs as virtual IPs. The VMs will get private IP addresses (the type that aren’t routed over the Internet). You would then use iptable’s NAT’ing or MASQUERADE’ing to forward traffic between IP addresses (or just ports, depending on your configuration requirements).


If you intend on making these VPS’ publically accessible, you really do need to have multiple “public” IP addresses, one for each of the VPS’.

There are technically other ways of gaining access to a VPS from primary IP address, but it gets really ugly really quickly, and there are limitations that you’d have to deal with.

Best Regards, Peter Knowles TPN Solutions

Email: pknowles@tpnsolutions.com
Phone: 604-229-0715 (new)
Skype: tpnsupport
Website: http://www.tpnsolutions.com

Ok, this is clear and it what I have asked for. I have one master IP and one or more Addon IPs (pubblic IPs).

How I have to skrew things up in Cloudmin in order to assign this pubblic IPs to the VPS´s private IP for back and forward communication? As writen above: Please also be aware bridged networking does not work here (at Server4You), for VMs, but a routed or NAT configuration will.