SSH / Borgbackup to IPV6 only using Proxyjump

allendiggity · August 2020

So, I got one of the free Euserv VPSs posted about here some time back, but have been looking for an actual use case that would work with my IPV4 only internet access.

https://euserv.com/en/virtual-private-server/root-vserver/v2/vs2-free.php

I use borgbackup as my backup solution, which does transfers over ssh. I have two paid VPS services that have both IPV4 and 6 addresses. I found this article dealing with SSH Proxyjump, that I didn't know about:
https://medium.com/maverislabs/proxyjump-the-ssh-option-you-probably-never-heard-of-2d7e41d43464

So, it turns out to be easy. In my .ssh/config, I've got something like:

Host paid-vps
HostName ipv4_address
Port 22
User root

Host euserv_free
HostName Ipv6_address
Port 22
User borgbackup
ProxyJump paid-vps

There are ssh keys set up on both servers. In order to SSH or borgbackup to the IPV6 only server, I just use the hostname euserv_free and it Just Works. Magic.