[root@bogon ]# pssh -H root@192.168.245.129 -i uptime
[1] 11:00:36 [FAILURE] root@192.168.245.129 Exited with error code 255
Stderr: The authenticity of host '192.168.245.129 (192.168.245.129)' can't be established.
RSA key fingerprint is 84:2d:70:33:1c:45:fa:e6:4b:94:72:7e:10:98:7c:a8.
Are you sure you want to continue connecting (yes/no)? 
Host key verification failed.

[root@bogon tmp]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
9e:14:9a:cc:8d:9b:fd:51:c5:68:24:e1:ce:c6:d7:33 root@bogon
The key's randomart image is:
+--[ RSA 2048]----+
|     o..  |
|     . o o  |
|    . . o o |
|   o = = . o  |
|   * S = o E |
|    * o o  o |
|   o + .   |
|     . .   |
|     .   |
+-----------------+

[root@bogon .ssh]# ll
total 8
-rw------- 1 root root 1675 Aug 22 11:06 id_rsa
-rw-r--r-- 1 root root 392 Aug 22 11:06 id_rsa.pub

[root@bogon .ssh]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.245.129
The authenticity of host '192.168.245.129 (192.168.245.129)' can't be established.
RSA key fingerprint is 84:2d:70:33:1c:45:fa:e6:4b:94:72:7e:10:98:7c:a8.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.245.129' (RSA) to the list of known hosts.
reverse mapping checking getaddrinfo for bogon [192.168.245.129] failed - POSSIBLE BREAK-IN ATTEMPT!
root@192.168.245.129's password: 
Now try logging into the machine, with "ssh 'root@192.168.245.129'", and check in:
 .ssh/authorized_keys
to make sure we haven't added extra keys that you weren't expecting.

[root@bogon .ssh]# pssh -H root@192.168.245.129 -i uptime
[1] 11:10:39 [SUCCESS] root@192.168.245.129
 20:10:39 up 2:07, 1 user, load average: 0.00, 0.00, 0.00