SSH

Create file

vim /etc/mybanner

Enable banner in /etc/ssh/sshd_config

Banner /etc/mybanner

X11

Install

yum install xauth

Connect

ssh -XYC <user_name>@<host_name>

Configuration

Host *
ForwardAgent no
ForwardX11 no
ForwardX11Trusted yes
Protocol 2
ServerAliveInterval 60
ServerAliveCountMax 30

Host <alias>
  HostName <host_name>
  User <user_name>
  port 22
  IdentityFile <path_to_key>

Host *
  User <user_name>
  port 22
  IdentityFile <path_to_key>