Tags
ssh
  1. ssh -Q kex
  2. ssh -G USER@HOST G ^kexalgorithms
  3. ssh -v USER@HOST #debug1: kex

vim /etc/ssh/sshd_config

AllowUsers *@123.456.789.* USER@IP

KexAlgorithms sntrup761x25519-sha512@openssh.com,curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256