SSH Optimization

Faster SSH Cipher#

The easiest optimization is to use blowfish.

Ubuntu#

Edit /etc/ssh/ssh_config.

Change 

#   Cipher 3des
#   Ciphers aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc

to 

Compression yes
Cipher blowfish
Ciphers blowfish-cbc,aes128-cbc,3des-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc

Verify by adding -v to the SSH command.

Multi-Core SSH#

Much much better with HPN-SSH.

See here for some directions on installation. I haven't yet made my own. (dead link)

See https://launchpad.net/~w-rouesnel/+archive/openssh-hpn also.

For long distance transfers, see http://sourceforge.net/projects/hscp/.

Even if you don't use NoneEnabled/NoneSwitch, you can double the speed of the transfer because ssh won't be bottle necked by a single core. Using NoneEnabled/NoneSwitch, you can about the same speed, but with less CPU consumption. 

$ time rsync -e \
    "ssh -v -o NoneEnabled=yes -o NoneSwitch=yes" \
    --progress --inplace --recursive \
    hostname:/home/username/somedir local_dir

Updated link

Linux.Shell : Networking : Mac.Shell : Performance : Networking.SSH