Using port number in Windows host file

Fiddler2 -> Rules -> Custom Rules

then find function OnBeforeRequest on put in the next script at the end:

if (oSession.HostnameIs("mysite.com")){
    oSession.host="localhost:39901";
    oSession.hostname="mysite.com";
}

I managed to achieve this by using Windows included Networking tool netsh.

As Mat points out : The hosts file is for host name resolution only, so a combination of the two did the trick for me.

Example

---

Overview

example.app:80
 |                           <--Link by Hosts File
 +--> 127.65.43.21:80
       |                     <--Link by netsh Utility
       +--> localhost:8081

Actions

• Started my server on localhost:8081
• Added my "local DNS" in the hosts file as a new line
  • 127.65.43.21 example.app
    • Any free address in the network 127.0.0.0/8 (127.x.x.x) can be used.
    • Note: I am assuming 127.65.43.21:80 is not occupied by another service.
    • You can check with netstat -a -n -p TCP | grep "LISTENING"
• added the following network configuration with netsh command utility
  • netsh interface portproxy add v4tov4 listenport=80 listenaddress=127.65.43.21 connectport=8081 connectaddress=127.0.0.1
• I can now access the server at http://example.app

Notes:
- These commands/file modifications need to be executed with Admin rights

- netsh portproxy needs ipv6 libraries even only to use v4tov4, typically they will also be included by default, otherwise install them using the following command: netsh interface ipv6 install

---

You can see the entry you have added with the command:

netsh interface portproxy show v4tov4

You can remove the entry with the following command:

netsh interface portproxy delete v4tov4 listenport=80 listenaddress=127.65.43.21

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Links to Resources:

• Using Netsh
• Netsh commands for Interface IP
• Netsh commands for Interface Portproxy
• Windows Port Forwarding Example

The hosts file is for host name resolution only (on Windows as well as on Unix-like systems). You cannot put port numbers in there, and there is no way to do what you want with generic OS-level configuration - the browser is what selects the port to choose.

So use bookmarks or something like that.
(Some firewall/routing software might allow outbound port redirection, but that doesn't really sound like an appealing option for this.)

What you want can be achieved by modifying the hosts file through Fiddler 2 application.

Follow these steps:

1. Install Fiddler2

2. Navigate to Fiddler2 menu:- Tools > HOSTS.. (Click to select)

3. Add a line like this:-

   localhost:8080 www.mydomainname.com

4. Save the file & then checkout www.mydomainname.com in browser.