Hello, I currently have a website that generates sub-domains for users but instead of creating them in cPanel I use wildcard sub-domains. I would like to have the sub-domains mirrored across 2 other domains so the sub-domain user1.domain1.com will also display if somebody visits user1.domain2.com and user3.domain3.net.

I found an old thread on a different site that was about 2 years old but the instructions didn't work for me. I'm running all 3 domains on my dedicated server running cPanel/WHM and CentOS 5.3 and currently have domain2.com and domain3.net setup as add-on domains for domain1.com. Any ideas?

Are you trying to create a URL fowarding service?
What I mean is that are you giving hosting with these domains?

Its is possible to create these subdomain with cPanel by creating a PHP script.

I am aware of that. I am running a forum hosting service and the script I am using uses wildcard sub-domains.

Each domain requires a dedicated ip address.
You will need to go into WHM, edit the DNS zone, and add
*.domain01.com ip01
*.domain02.com ip02
*.domain03.com ip03

http://www.actiononline.biz/web/enabling-wildcard-dns-on-cpanel-servers/

is a pretty precise guide on how to achieve it with WHM.

Thanks, I will give that a try. It's a good thing I have plenty of IP addresses on this server going unused. :D

That link you posted cselzer doesn't look like it will do what I'm trying to do. According to the page it will make all domains and subdomains point to the main site.

That link you posted cselzer doesn't look like it will do what I'm trying to do. According to the page it will make all domains and subdomains point to the main site.

It was meant to point you to the direction where to add the wildcard subdomains, you would have to alter it a little bit. If you don't fully understand on how to do it, you may want to look into paying someone a few bucks to do it as its only a 15 minute max job. I would be willing, but my time restraints hinder that, so i'm sorry.

Just google wildcarded subdomains and you would be able to find a guide pretty easily.

I have my wildcard subdomains setup and working properly, it's only 2 clicks and a keystroke with cPanel. :)