We have a website hosted on port 80 with the name www.abcabc.com. Now we want to host another website on port 1111 with name www.xyzxyz.com and expose it to the internet. When i asked my DNS team they said they can Only redirect a domain name to the IP address and they cannot do port forwarding. Is it possible to run 2 different instances on separate ports accessible with different domai name. I have head that host header can be changed to accommodate this? Any help will be appreciated.
Your DNS team is correct. DNS doesn't care about the port number (except in SRV records, which doesn't matter here).
If you want both sites accessible on the same IP using IIS, you bind them both to port 80, but change the host header for each site to their FQDN. This will break SSL, though, so you can only do this with regular HTTP traffic.
If you must run them on different ports, you'll need to put a reverse proxy in front of your web server to intercept all traffic to
www.xyzxyz.com:80 and redirect it to your internal server on
You will want to check on the Bindings for the website.
In IIS Management Console -> Sites -> the website you want on port 111 -> Right click and choose Binding -> Add binding, choose your settings and change the Port option to 1111.