Persistent SSH connection via SSH ControlMaster.

config

## add following to mac ~/.ssh/config file after required edits
## then do ssh mcclearybg to start background session, typically
## once per day. This will require duo push
## then you can start additional ssh by ssh mccleary (note: no suffix bg)

## More at https://docs.ycrc.yale.edu/clusters-at-yale/access/advanced-config/ and
## https://www.anchor.com.au/blog/2010/02/ssh-controlmaster-the-good-the-bad-the-ugly/

################## Yale ##################
# Uncomment the ForwardX11 options line to enable X11 Forwarding by default (no -Y necessary)
# On a Mac you still need xquartz installed

## EditMe:
# for ControlMaster: make ControlPath dir, e.g., mkdir -p ~/.ssh/tmp
# replace User: foo with your netid

Host *.hpc.yale.edu farnam grace milgram ruddle
    User foo
	ServerAliveInterval 40
	StrictHostKeyChecking no
	Compression yes
#   ForwardX11 yes

Host farnam grace milgram ruddle
	HostName %h.hpc.yale.edu

Host *.ycrc.yale.edu mccleary
    User foo
	ControlMaster auto
	ControlPath ~/.ssh/tmp/%h_%p_%r.sock
	ControlPersist 10s
	ServerAliveInterval 40
	StrictHostKeyChecking yes
	Compression yes
#   ForwardX11 yes

Host mccleary
	HostName %h.ycrc.yale.edu

Host mcclearybg
	HostName mccleary.ycrc.yale.edu
    User foo
	ControlMaster auto
	ControlPath ~/.ssh/tmp/%h_%p_%r.sock
	ControlPersist 10s
	ServerAliveInterval 40
	StrictHostKeyChecking yes
	Compression yes
	ExitOnForwardFailure yes