IPv6 not changing during connection

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LonnieTC
Posts: 20
Joined: Sun Sep 17, 2017 4:36 pm

IPv6 not changing during connection

Post by LonnieTC » Tue Sep 28, 2021 11:31 am

Hi All,

I am still a bit new to SoftEther VPN and have been trying learn a bit over the years as well as have setup a small SoftEther VPN test server on a Linux (Ubuntu 20.04) VPS server that I have online.

The IPv4 connections from my Windows 10 machine using the seem to work well and I get back a new IP without any problems, but have noticed that when I connect to the server then my IPv6 does not change. I also notice that if I connect to a SoftEther VPN Gate server that the IPv6 does not change as well.

I think that leaves a hole in the security to have the IPv4 changing but not the IPv6, although I could be wrong on this and was wondering if there is a way to make the IPv6 address change as well?

Any input would be greatly appreciated.
Thanks in advance

eddiewu
Posts: 149
Joined: Wed Nov 25, 2020 9:10 am

Re: IPv6 not changing during connection

Post by eddiewu » Tue Sep 28, 2021 11:41 am

Please clarify your issue.
1. The remote network (VPS) has IPv6 support and are assigning IPv6 addresses to clients. You want to use that.
2. You have IPv6 address locally and want to block it when connecting to the VPN. (to avoid IPv6 leak)\
Which one do you want?

LonnieTC
Posts: 20
Joined: Sun Sep 17, 2017 4:36 pm

Re: IPv6 not changing during connection

Post by LonnieTC » Tue Sep 28, 2021 1:09 pm

Hello,

You raise a good point that I really had not thought about heavily.

I guess the simplest case might be number 2 which would be to simply block the IPv6 when connecting to the VPN.

Thanks again

eddiewu
Posts: 149
Joined: Wed Nov 25, 2020 9:10 am

Re: IPv6 not changing during connection

Post by eddiewu » Wed Sep 29, 2021 1:16 am

IPv6 routing table is not managed in the stable version of SoftEther client. You need to manually disable IPv6 in Windows to avoid the leak.
Alternatively, you can install the developer version which has that feature but it can't connect to vpn gate servers.
Latest developer version can be found here: (Installers - Download artifacts)
https://dev.azure.com/SoftEther-VPN/Sof ... dArtifacts

LonnieTC
Posts: 20
Joined: Sun Sep 17, 2017 4:36 pm

Re: IPv6 not changing during connection

Post by LonnieTC » Wed Sep 29, 2021 10:33 am

Thanks for the reply on this and it sounds like the development version is already addressing this type of question.

Do you know if the development version has any plans to eventually be able to connect to the VPN Gate servers as well since that would be desirable too?

Thanks again

Mehtaji
Posts: 2
Joined: Thu Sep 30, 2021 11:45 am

Re: IPv6 not changing during connection

Post by Mehtaji » Thu Sep 30, 2021 11:53 am

would be to simply block the IPv6 when connecting

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