Zhang Yunlu gazhikaba

Overview

Internet connection and DNS routing are broken from WSL2 instances, when some VPNs are active.

The root cause seems to be that WSL2 and the VPN use the same IP address block, and the VPN routing clobbers WSL2's network routing.

This problem is tracked in multiple microsoft/WSL issues including, but not limited to:

Create Root CA (Done once)

Last update: Nov 2025.

Create Root Key

Attention: this is the key used to sign the certificate requests, anyone holding this can sign certificates on your behalf. So keep it in a safe place!

openssl ecparam -genkey -name secp384r1 | openssl ec -aes256 -out rootCA.key

Here are several different ways to test a TCP port without telnet.

BASH (man page)

$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C

$ cat &lt; /dev/tcp/127.0.0.1/23

	#!/usr/bin/env python

	"""Simple HTTP Server With Upload.

	This module builds on BaseHTTPServer by implementing the standard GET
	and HEAD requests in a fairly straightforward manner.

	"""

	package laccetti.test;

	import org.apache.qpid.server.Broker;
	import org.apache.qpid.server.BrokerOptions;

	import com.google.common.io.Files;

	/**
	* We shouldn't need external things for testing
	*/

	<NotepadPlus>
	<UserLang name="Scala" ext="scala" udlVersion="2.0">
	<Settings>
	<Global caseIgnored="no" allowFoldOfComments="no" forceLineCommentsAtBOL="no" foldCompact="no" />
	<Prefix Keywords1="no" Keywords2="no" Keywords3="yes" Keywords4="no" Keywords5="no" Keywords6="no" Keywords7="no" Keywords8="no" />
	</Settings>
	<KeywordLists>
	<Keywords name="Comments" id="0">00// 01 02 03/* 04*/</Keywords>
	<Keywords name="Numbers, additional" id="1"></Keywords>
	<Keywords name="Numbers, prefixes" id="2">0x</Keywords>

	#!/usr/bin/env python

	"""Simple HTTP Server With Upload.

	This module builds on BaseHTTPServer by implementing the standard GET
	and HEAD requests in a fairly straightforward manner.

	"""

	<NotepadPlus>
	<UserLang name="Gradle" ext="gradle">
	<Settings>
	<Global caseIgnored="yes" />
	<TreatAsSymbol comment="yes" commentLine="yes" />
	<Prefix words1="no" words2="no" words3="no" words4="no" />
	</Settings>
	<KeywordLists>
	<Keywords name="Delimiters">"'0"'0</Keywords>
	<Keywords name="Folder+"></Keywords>

	#! /usr/bin/env python

	import SocketServer
	import SimpleHTTPServer
	import urllib2
	from urlparse import urlparse, urljoin

	PORT = 8880
	FOLLOW_REDIRECT = True
	PROXY_RULES = {