Host                = *
ControlMaster       = auto
ControlPath         = /home/javafan/.ssh/ssh_%h_%p_%r

Host                = gateway1
HostName            = gateway1.example.com
User                = javafan
ForwardAgent        = yes
ServerAliveInterval = 60

Host                = gateway2
Hostname            = gateway2.example.com
User                = javafan
ForwardAgent        = yes
ProxyCommand        = ssh gateway1 nc %h %p

Host                = *.example.com
ForwardAgent        = yes
User                = javafan
ProxyCommand        = ssh gateway2 nc %h %p