cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
sed -i '/UseDNS/cUseDNS no' /etc/ssh/sshd_config
sed -i 's/GSSAPIAuthentication yes/GSSAPIAuthentication no/' /etc/ssh/sshd_config
systemctl restart sshd
cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
sed -i '/UseDNS/cUseDNS no' /etc/ssh/sshd_config
sed -i 's/GSSAPIAuthentication yes/GSSAPIAuthentication no/' /etc/ssh/sshd_config
systemctl restart sshd