Ssh linux
From Teknologisk videncenter
ssh without a passphrase
On the main host:
ssh-keygen
ssh-copy-id beagle@192.168.100.202
or
$ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa
$cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
$chmod 0600 ~/.ssh/authorized_keys
sshguard
sshguard protects hosts from brute-force attacks against SSH and other services. It aggregates system logs and blocks repeat offenders using one of several firewall backends.