Forward X11 from a ipv6 host to a ipv4 client

Since my new ISP uses ipv6 I was confronted with the problem: How should I use my remote x11 window to test software (Xephyr in my case) when the clients ISP does not support ipv6.

Thanksfully my vservers supports ipv6. In this combination I was able to put up a ipv4 -> ipv6 gateway with X11 forwarding.

Note: This method does also work with more than one gateway and ipv4 only

Here my setup:

  • A - my Client
  • B - my Server
  • C - the remote host I want to connect with X11 forwarding

The ipv6 synatix in ssh looks like: \[x:x:x:x\]

Create a tunnel to C via B from A

ssh -N -L <someport>:user@A:<portofC> user@B &

Connect to remote Host via tunnel

ssh -X userFromC@localhost -p <someport>

Yeay ready to use X11 forwarding!!!

To speed up the connection you can set some option on which encryption method is used!

Currently I’m using: ssh -XC -c blowfish-cbc,arcfour

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