Heey all!

This is my situation:
I have a domain at lets say Company A.
I have a VPS (Virtual Private Server) with Debian on it at Company B.

I have ZNC (a IRC Bouncer) running on the VPS.
But every time a user connects trough the bouncer to a IRC server he gets the host *!*@vps123.companyb.com.

Lets call the domain I have at Company A "www.vhost.com".

Now this is what I want:
I want to use that domain for a VHOST for the bouncer so everytime a user connects, his host isnt *!*@vps123.companyb.com but *!*@vhost.com.

The only problem is, I have totally no experience with making VHOSTs.

My question is, what do I have to do at Company A and at Company B to get that VHOST to work with my bouncer?
I already read some things about rDNS (Reverse DNS) but I never did stuff like that so I dont know where to start and what to do.

Could someone please explain this to me or give me a link to a guide/tutorial how I fix all this?

Thanks in advance!

Updating rDNS does indeed sound like what you're looking for. I don't know what VPS hosting company you're using, but if they gave you a dedicated IP then they usually have some place in their control panel to updated rDNS.

--jeremy