ssh jump host forwarding config

ssh_jumphost_config.txt

#
# see also: 
# https://en.wikibooks.org/wiki/OpenSSH/Cookbook/Multiplexing
# http://blog.scottlowe.org/2015/12/11/using-ssh-multiplexing/
#
# you may want to use connection multiplexing on the jumphost
Host jump-host
Hostname jump-host.example.com
ForwardAgent yes
ControlPath ~/.ssh/cm-%r@%h:%p
ControlMaster auto
ControlPersist 10m

# this can also be chained, i.e. local->target_host->target_host2->...
Host target-host
ProxyCommand ssh -W %h:%p jump-host

# one-liner:
# ssh -o ProxyCommand="ssh -W %h:%p proxy_host" target_host