IIS 6 can be setup to host mutiple websites using the same IP address using Host Headers. If the site only runs on port 80 (i.e. only uses http:// not https://) this can be setup using the Internet Information Services (IIS) Manager's "Advanced Web Site Identification" dialog. If one or more of the websites hosted on the IP address uses port 443 (i.e. https:// or SSL), the Host Headers must be configured using a command line tool.
Configuring Server Bindings for SSL Host Headers (IIS 6.0)
cscript.exe adsutil.vbs ENUM /P /W3SVC/
Copyright (C) Microsoft Corporation 1996-2001. All rights reserved.
[/W3SVC/AppPools]
[/W3SVC/Info]
[/W3SVC/1]
[/W3SVC/Filters]
[/W3SVC/260116085]
[/W3SVC/2123871385]
[/W3SVC/721699136]
cscript.exe adsutil.vbs ENUM /W3SVC/<site identifier>/
Copyright (C) Microsoft Corporation 1996-2001. All rights reserved.
ServerState : (INTEGER) 2
ServerComment : (STRING) "GenerationsUnite"
ServerAutoStart : (BOOLEAN) True
ServerBindings : (LIST) (2 Items)
"192.168.64.7:80:www.mysite.com"
"192.168.64.7:80:mysite.com"
":443:www.mysite.com"
":443:mysite.com"
…
[/W3SVC/260116085/filters]
[/W3SVC/260116085/root]
cscript.exe adsutil.vbs set /w3svc/<site identifier>/SecureBindings ":443:<host header>" [<additional bindings>]