By default the root ssh login to Ubuntu 14.04 Linux server is disable. This is a security feature and even though you chnage the root password the root ssh login will be denied showing message similar to the one below:
$ ssh root@10.1.1.12 root@10.1.1.12's password: Permission denied, please try again. root@10.1.1.12's password: Permission denied, please try again. root@10.1.1.12's password: Permission denied (publickey,password).
In order to allow a root SSH login on Ubuntu 14.01 Linux server/desktop the sshd daemon’s config file /etc/ssh/sshd_config needs to be changed. Open /etc/ssh/sshd_config and make a following changes to the line specified below:
FROM: PermitRootLogin without-password TO: PermitRootLogin yes
Once you have made the change, restart the SSHD service for those changes to take affect:
# service ssh restart ssh stop/waiting ssh start/running, process 6919
Once done you can SSH login to ubuntu server:
$ ssh root@10.1.1.12 root@10.1.1.12's password: Welcome to Ubuntu 14.04 LTS (GNU/Linux 3.13.0-24-generic x86_64)