Cannot use ssh without password prompt

I am trying to set up a cron job to perform nightly backups from one linux
server to another using rsync.  Everything is working fine except that I
cannot get it to work without first prompting for a password, which of
course kills the whole cron idea.  Googling, I have found about ten examples
that I have followed.  They are all the same.  My steps to sync server2 with
server1:



On server2, use ssh-keygen to generate a key pair.

scp the public key to server1

On server1, create .ssh/authorized_keys file containing the public key from
server2

Adjust permissions:  700 for .ssh directories on both machines, 600 for
authorized_keys on server1 and the private key on server2

The rsync invocation uses IP addresses, not machine names and explicitly
references the private key on server2

(e.g. rsync  -avz  -e  /usr/bin/ssh  -i ~user/server2-rsync-key
<user>@1.2.3.4:path-to-source/  path-to-dest)



Troubleshooting, I have also tried the following:

Used rsa keys instead of dsa

Renamed authorized_keys authorized_keys2

In /etc/ssh/sshd_config on server1:

AuthorizedKeysFile      <user>/.ssh/authorized_keys

PubkeyAuthentication    yes



What am I missing?



Mike Clay

Configuration Manager

ESPRH Solutions, Inc.

(214) 774-4213