Private IP Address Question

Virtualmin
1

Hi

I’m a little confused as to how to change the IP address of a virtual server that has a dedicated IP.

I thought it would be vm >> Addresses and Networking >> Change IP Addresses. But it says this is just for “non private IP virtual servers”.

Is it edit virtual server >> configurable settings >> external IP address? The ‘help’ text for this seems to suggest it’s for something different.

My server is VM pro on CentOS 6

2

Howdy,

To change the IP for one Virtual Server, you can go into Server Configuration -> Change IP Address.

From there, you can add your new IP to “New IP address” in the “Use private address” field.

-Eric

3

Hi Eric

I only see a field for “Use private IPv6 address”.

Perhaps I have to go to webmin >> network configuration first, and add the IP address there before it will appear as an option?

4

Nope, you don’t need to add it in Webmin first.

In Server Configuration -> Change IP Address, you should see an option to add both “New IP address” as well as “New IPv6 address”.

I have a few questions regarding your setup:

  1. What Virtualmin version are you using?

  2. What Linux distribution and version do you have?

  3. How did you perform the Virtualmin installation – was it with the install.sh script?

-Eric

5

I am on CentOS Linux 6.2 Linux 2.6.32-71.29.1.el6.x86_64 on x86_64 fully patched + 3.90 Pro. VM installed by install script.

I have checked on my other production server and it’s the same. What I notice is this:

  1. If a virtual server is on a shared IP, then there is an option “Use private address”.

  2. If the virtual server is already using a private address, then that option is not there. The options are either “Keep private address” or go to shared IP address. You cannot enter a new private IP address.

6

This works: First change the server with private IP to use a shared IP. Then the option to change to private IP is available. When I tested that, there did not seem to be any problems.

i.e. Needs a two-step process. You can’t directly change one private IP to another.

7

What is a private IP? I have a server that has 5 IP’S. What is a shared vs. private IP?

Thanks

8

A private IP is an IP address that’s only allowed to be used for just one domain – this is often used when giving a domain an SSL certificate.

A shared IP can be used for any number of domains.

-Eric

9

Thanks Andrey as always.

How can we create a private IP? Does a private IP mean that it is a separate NIC?

I have one NIC with 6 IP’s bound to it such as eth0:0, etho:1 etc. Now all these IP’s show up in the shared IP dropdown.

Can you advise?

\|/

10

It uses an ethernet alias, such as what you described above. So if your main IP is on eth0, it would create an alias “eth0:0”.

To setup a domain with a private IP, you can go into Server Configuration -> Change IP Address, and set the desired IP there.

-Eric