I do a lot of local development with Internet Information Services and either ColdFusion, PHP or ASP.net and for the longest time I would actually run the websites on separate ports on 127.0.0.1.

Unfortunately running multiple websites on various other ports causes some issues like:

• Port conflicts with other programs
• Remembering which port is used for what website
• Causes problems with some websites that look for port 80
• Doesn’t really work with SSL (port 443)

So what I started doing was running my websites on separate private IP addresses which are local to my machine only, and this worked GREAT! I could load up websitexyz, bind it to IP 1.1.1.10, setup SSL to work on port 443 for 1.1.1.10 and I would go about my business.

The only downside was when I would run out of IP addresses, because I would only add about 5 to 10 IPs at a time to my local loopback adapter. It is a bit of a pain in the butt to add a bunch of IP addresses in Windows, so it would take me a bit of time to do this everytime I needed more IPs.

That was until I ran into a small batch script which can add as many IP addresses as I want in a range.

Here’s the code:

FOR /L %A IN (41,1,100) DO netsh interface ipv4 add address “ColdFusion-IIS” 1.1.1.%A 255.255.255.0

Simply copy that into either a command prompt or a .bat file and run it to add as many IP addresses in a range that you want.

Here’s the break down of the script:

FOR /L %A IN (START,INCREMENT,END) DO netsh interface ipv4 add address “INTERFACE_NAME” IPMASK SUBNET

If we take a look at my script above we see that

• START = 41
• INCREMENT = 1
• END = 100
• INTERFACE_NAME = ColdFusion-IIS
• IPMASK = 1.1.1.%A
• SUBNET = 255.255.255.0