SSH password-free login between Linux

First, generate a public private key pair

$ ssh-keygen -t rsa -p  ' Generating public/private rsa key pair. enter file in which to save the key  (/ROOT/.SSH/ID_RSA):  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:88:64:ed:a1:a7:a2:c0:b4:ee:77:38:2f:c7:39:c6:c1 [email protected]the key ' s  RANDOMART IMAGE IS:+--[ RSA 2048]----+|                  | |      .           | |     o o          | |    o + o         | |  .  + + s        | | o .  e           | |. o. = o          | | o. * o           | | Oo. b.           |+-----------------+ -p phrase    Provide old passphrase.  this refers to the password that uses the private key  -t type      specify type of key to create.  This is the type of public private key created  $ ll .ssh/total 8 -RW-------.  1 root root 1675 sep  6 04:12 id_rsa-rw-r--r--.   1 root root  394 sep  6 04:12 id_rsa.pub

Second, copy the public key to password-free login machine

$ ssh-copy-id [Email protected]the authenticity of host ' 172.17.5.46 (172.17.5.46) ' can ' t be established. RSA Key fingerprint is 8e:ac:89:5d:10:be:e7:d8:a2:34:0b:bf:70:cd:ce:33.are your sure you want to continue connecting (yes/n o)? yeswarning:permanently added ' 172.17.5.46 ' (RSA) to the list of known hosts. [email protected] ' s Password:now try logging into the machine, with "ssh" [email protected] ' ", and check in:. Ssh/author Ized_keysto Make sure we haven ' t added extra keys and you weren ' t expecting.

Login-Free machine:

$ LL. ssh/total 4-RW-------. 1 root root 394 Sep 6 04:16 Authorized_keys

Third, testing

# SSH 172.17.5.46Last Login:sun Sep 6 04:06:43 from 172.17.5.45[[email protected] ~]#

Successful password-free login.

Iv. Conclusion

1. Password-free login does not have to enter the password every time, convenient many;

2. Rsync can also use SSH authentication to transfer files between Linux servers without password;

3. It is best not to configure password-free login for root user
   

SSH password-free login between Linux