Public Key Authentication
Public Key Authentication is helpful because it increases security while at the same time allowing you to log in without typing your password. A good reference on setting up Public Key Authentication is here.
For those of you that use openssh to login with Cygwin, here is a helpful reference.
Intra-cluster
If you would like to be able to ssh between cluster machines without having to use passwords you should be able to do this when just logged in:
cd .ssh ssh-keygen -t rsa -b 4096 -f id_cluster_rsa
this will generate two file id_cluster_rsa (the private key) and id and ask for a password. for passwordless logins leave it blank
cat id_cluster_rsa.pub >> authorized_keys
Then you when ssh-ing between nodes, you need to tell ssh to use your identity file (private key). There are two methods
1. If you never ssh out of the cluster then
ln --symbolic id_cluster_rsa id_rsa
2. If you ssh from the cluster to non-cluster machines and use different keys when connecting to different machines (a good security practice), then you can also create a ~/.ssh/config file which will use that particular key for econ hosts then you don't have to do a ssh -i
Host econ0 HostName econ0 User putyourusernamehere IdentityFile ~/.ssh/id_cluster_rsa Host econ1 HostName econ1 User putyourusernamehere IdentityFile ~/.ssh/id_cluster_rsa Host econ2 HostName econ2 User putyourusernamehere IdentityFile ~/.ssh/id_cluster_rsa etc.