Windows 10: Does the hosts file support IPv6 addresses?

I am making a program that automatically adds and deletes lines to the Windows hosts file. So lets says you are working on example.com, and you have apache setup with a virtual host that runs example.com, you can click my script, and it will add:127.0.0.1 example.com to the hosts file, the runs ipconfig /flushdns.And when you run it again, it deletes the sites. You can send command line flags to always enable or always disable, but the default behavior is to toggle them, so you can quickly go from seeing the local version to seeing the live version.It starts by reading in the existing hosts f

:)

 

Chrome not using hosts file for IPv6 addresses since v73

There is a know bug in Chrome which might be responsible for your problem:

Issue 530482: Can't reach private IPv6 hosts on networks without global IPv6 connectivity.

The discussion in the bug report clarifies that Chrome launches an IPv6 probe to
determine if there is IPv6 support, by checking with a remote address.
If that IPv6 probe fails, Chrome will mask out any other IPv6 results,
in effect disabling IPv6 and ignoring it forever.

The explanation is then that if IPv6 support is sketchy on the network,
so that this single initial IPv6 probe done by Chrome fails,
Chrome will just disable IPv6 resolving totally, including local IPv6
resolving from the hosts file.

A workaround mentioned is:

Other more limited workarounds are mentioned at the end of the bug report.

The bug report dates from 2015, but was still alive in May 2019,
so it may perhaps be currently in process.

 

Chrome not using hosts file for IPv6 addresses since v73

Your hosts file should be consistent, eg; localhost is 127.0.01. Then some-project.test should also be available on 127.0.0.1, and since the IPv6 address ::1 typically, and traditionally also points to localhost, and the IPv4 address 127.0.0.1. As not all systems are necessarily IPv6 capable -- yes, even in this day, and age.

The problem, like localhost is that test is a TLD (just like .com).

My suggested hosts file:

See what I'm talking about? Some applications (and OSs) assume a localhost "host". So you may find you require an entry for it -- see; optional in the example above.

Lastly. Make sure your resolver flushes it's DNS cache. As to your system. It should see the change(s) immediately. But you should check first.

 

Temporary IPv6 Address Creation and logging

I have seen wide differences in the way some hosts create their temporary IPv6 addresses. Some only have a few, while some have hundreds. This leads me to trying to find the answers to several questions, which so far have eluded me. I am aware that this
feature can be disabled, and that is the only responses I seem to be able to find, but I want to understand the process behind their creation.

1. Specifically what triggers the creation of a new Temporary address.
   1. Is this something that is controlled at the OS level, or do applications have a say on when a new address is created.
   2. Why do some hosts create a new one every few seconds, and have hundreds active, while some have only one or two.
2. What triggers the deletion of an old address, with the same sub questions as (1)?
3. How do I log the fact that a new address has been created, for later auditing, and what triggered it? If I have hundreds of hosts, on my network, I need to be able to retrospectively ascertain who was the source of malicious traffic.
4. How can I identify which process(es) is responsible for creating the hundreds of addresses?
5. How do the parameters below affect address generation and deletion
   1. C:\WINDOWS\system32>netsh interface ipv6 show privacy
      
      Querying active state...
      
      Temporary Address Parameters
      
      ---------------------------------------------
      
      Use Temporary Addresses : enabled
      
      Duplicate Address Detection Attempts: 3
      
      Maximum Valid Lifetime : 7d
      
      Maximum Preferred Lifetime : 1d
      
      Regenerate Time : 5s
      
      Maximum Random Time : 10m
      
      Random Time : 1m57s
6. If I enter the command netsh interface ipv6 show addresses I get a long list of addresses with the same
   valid life and pref life. Why?

A lot of questions, Sorry about that, but I am hoping if anyone can answer them, it can help many people understand this strange behaviour, that seems to plague many people.

Kind Regards