I’ve my server running on multiple Ipv6 and Ipv4. However, after several years, never crossed in my mind to enable Ipv6 on my sshd.
One of my host hooked up to my server have quite interesting host and with short char. By adding ipv6 enable on my sshd, able to reduce my lil time whenever i want to connect to my server without typing long char host running on the same server with Ipv4.
I did some comparison between Ipv4 and Ipv6 authentication, and found out there are some latency from Ipv6 compare then Ipv4 on sshd. By logic Ipv6 does not give any impact on speed up or slow down the network layer.
My wild guess, this should be the sshd itself. I will try to find it out and update this post.