Unable to connect BeagleBone Black on Linux Red hat.

I tried to run following commands in terminal to connect the Beaglebone black with my pc having red hat installed:

$ ssh debian@

Then I entered the password “temppwd” for username “debian” and following is the response for it.

debian@’s password:

Permission denied, please try again.

Is this username and password applicable for linux or any else?

I also tried to get root access for BBB by running following command,
$ ssh root@

After entering the empty password, response was the same as above case. I have done necessary changes in “sshd_config file” such as PermitRootLogin yes from no(initially it was “no”) to enable root login over ssh.

I am unable to figure out whats going wrong. Please help how to start Beagle bone black with linux Red hat.