How To SCP Between Servers Without Passwd Authentication

First of all, we need to generate rsa private key and public key for the source server (vice versa).

ssh-keygen -t rsa

then just hit enter until 2 files is generated in /root/.ssh/ :

1. id_rsa
2. id_rsa.pub

then copy the value of id_rsa.pub into /root/.ssh/authorized_keys in any related servers

after that u can scp to the targeted server without passwd authentication :

1. to get file :

scp root@192.168.2.1:/opt/example /opt

2. to get directory and its content :

scp - r root@192.168.2.1:/opt/example /opt

3. to send file :

scp /root/example root@192.168.2.1:/root

4. to send directory and its content :

scp -r /root/example root@192.168.2.1:/root