While connected to VPN the curl command hangs up

[Darkside81]

OK: From our office and from home remotely, we can use the VPN connection, curl succeeds.
OK: While visiting our customer's office, without using the VPN connection, curl also succeeds.
FAIL: While visiting our customer's office, when using the VPN connection, curl hangs as follows:

$ curl ifconfig.co; curl -vvv https://testlink.limelightbox.com 
198.199.107.195 
* Rebuilt URL to: https://testlink.limelightbox.com/ 
* Trying 52.39.78.238... 
* TCP_NODELAY set 
* Connected to testlink.limelightbox.com (52.39.78.238) port 443 (#0) 
* ALPN, offering h2 
* ALPN, offering http/1.1 
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH 
* successfully set certificate verify locations: 
* CAfile: /etc/ssl/cert.pem 
CApath: none 
* TLSv1.2 (OUT), TLS handshake, Client hello (1):

Above simply hangs.

Can someone assist with advice

[craigloewen-msft]

What build of Windows are you using? And are you using WSL 1 or WSL 2?

[therealkenc]

Also maybe try Windows curl.exe with the VPN up and see if that takes, just for the datapoint. Eliminates WSL if it doesn't work. Points finger at WSL if it does.

This issue has been automatically marked as stale because it has marked as requiring author feedback but has not had any activity for 7 days. It will be closed if no further activity occurs within 7 days of this comment. Thank you for your contributions to WSL!

[zot]

I'm having a similar issue with our VPN.

Git and SSH both hang over the VPN from WSL but both work just fine from within Windows.

Windows version: Microsoft Windows [Version 10.0.18990.1]

The VPN client is Shrew Soft standard edition version 2.2.2.

By the way, I've been using this VPN client version with a VMware Linux VM for years just fine, NATing through windows.

[Darkside81]

I'm using WSL 2

[craigloewen-msft]

@Darkside81 and @zot could you please take networking logs of the issue that you're seeing? Instructions on how to do so are here. Please comment back on this thread with a link to your feedback item and we can take a look at what might be causing it! Thanks!

[zot]

OK, here's the link.

In the test, I was able to make a regular HTTP connection (we don't have HTTPS running internally) through our VPN but I could not SSH.

[zot]

I'm able to use services on our VPN by port-forwarding with SSH from within Windows-land. Maybe other people with this problem can use a similar technique. Here's my script (run it from git-bash/msys/cygwin):

#!/bin/sh
MAIL_HOST=YOUR-MAIL-HOST
SSH_USER=YOUR-USER-NAME
SSH_HOST=YOUR-VPN-SSH-HOST
ADDR=$(ipconfig|sed '/WSL/ {N;N;N;N;s/\n//g;s/^.*: \([^:]*\)$/\1/;p};d')
echo $ADDR
exec ssh -L $ADDR:11000:$MAIL_HOST:110 -L $ADDR:2500:$MAIL_HOST:25 $SSH_USER@$SSH_HOST

It just finds the ip addr of the WSL adapter, prints it out, and uses SSL to port-forward 11000->110 and 2500->25 on it.

Configure your Linux email client to use the printed IP address and port 11000 for pop, 2500 for outgoing.

Note that the WSL switch changes IP every time you boot: #4150

I have a second workaround for this, I created a NAT switch Hyper-V Manager and I actually use that instead of the WSL adapter (my script uses Ethernet NAT instead of WSL). It has a static IP, so it doesn't change every time I boot.

[timesnewmen]

I'm able to use services on our VPN by port-forwarding with SSH from within Windows-land. Maybe other people with this problem can use a similar technique. Here's my script (run it from git-bash/msys/cygwin):

#!/bin/sh
MAIL_HOST=YOUR-MAIL-HOST
SSH_USER=YOUR-USER-NAME
SSH_HOST=YOUR-VPN-SSH-HOST
ADDR=$(ipconfig|sed '/WSL/ {N;N;N;N;s/\n//g;s/^.*: \([^:]*\)$/\1/;p};d')
echo $ADDR
exec ssh -L $ADDR:11000:$MAIL_HOST:110 -L $ADDR:2500:$MAIL_HOST:25 $SSH_USER@$SSH_HOST

It just finds the ip addr of the WSL adapter, prints it out, and uses SSL to port-forward 11000->110 and 2500->25 on it.

Configure your Linux email client to use the printed IP address and port 11000 for pop, 2500 for outgoing.

Note that the WSL switch changes IP every time you boot: #4150

I have a second workaround for this, I created a NAT switch Hyper-V Manager and I actually use that instead of the WSL adapter (my script uses Ethernet NAT instead of WSL). It has a static IP, so it doesn't change every time I boot.

How can you set the WSL VM use the "NAT Switch" you have created?