I would like to be able to use ssh user@host without the -i identity_rsa_or_else_private_key_file . Is there a place somewhere in ssh configs where I can point where are the private keys located so that the ssh will automatically choose one for the connection (so that I don't have to type -i key_file)?
How to point to ssh folder with private keys to automatically choose one?
ssh;key authentication
I suggest reading the ssh_config man page.  If you want to have a specific identity per-host, and another for all other hosts, do something like this in your ~/.ssh/config:Host hostname.example.com    IdentityFile ~/.ssh/identity_rsa_or_else_private_key_fileHost *    IdentityFile ~/.ssh/another_identity_fileBy default, it uses ~/.ssh/id_rsa for the IdentityFile for RSA identities and ~/.ssh/id_dsa for DSA identities, so if you don't want to change your ~/.ssh/config, you can just rename the file to that name.