I have the following scenario:

My url for Share Point Portal Server is:

http://machinename:XXXX <http://machinename:XXXX/>

where 'XXXX' is a port number.

Now we plan to assign it a URL (we already have a real ip assigned to it) so
that it can be accessed via the Internet, but the operations dept. has sent
me the following problem i.e.:

"URL redirection on port other then 80 is not possible through DNS. I will
appreciate if you can redirect all the port 80's traffic towards port XXXX"

Now we have already some sites running of port 80 and I don't want to mix up
our portal resources with those sites... can anyone provide me any help on
how I can get a work around. I believe I can set the "HOST HEADERS" option
available via IIS 6 .but will there be any issues arising on the sharepoint
portal as a result of it ? and is there any other way of achieving it ?

How to use Host header articles are:

http://www.visualwin.com/host-header/

http://msmvps.com/bernard/archive/2004/07/29.aspx