1) ssh-keygen 사용시 문제점.. 
 [root@meconfidence root]# ssh-keygen 
You must specify a key type (-t). 
Usage: ssh-keygen [options] 
Options: 
  -b bits     Number of bits in the key to create. 
  -c          Change comment in private and public key files. 
  -e          Convert OpenSSH to IETF SECSH key file. 
  -f filename Filename of the key file. 
  -i          Convert IETF SECSH to OpenSSH key file. 
  -l          Show fingerprint of key file. 
  -p          Change passphrase of private key file. 
  -q          Quiet. 
  -y          Read private key file and print public key. 
  -t type     Specify type of key to create. 
  -B          Show bubblebabble digest of key file. 
  -C comment  Provide new comment. 
  -N phrase   Provide new passphrase. 
  -P phrase   Provide old passphrase. 
[root@meconfidence root]# 
 
---> 에러는 나지 않는데요, 키 생성이 안되네요.,., 
 
2) 인증키 사용법
 
 [root@dolgaroo root]# ssh-keygen
Generating public/private rsa1 key pair.
Enter file in which to save the key (/root/.ssh/identity):
/root/.ssh/identity already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/identity.
Your public key has been saved in /root/.ssh/identity.pub.
The key fingerprint is:
13:ea:88:b4:b0:d4:c2:90:28:93:be:19:1d:4e:b2:ba root@dolgaroo [root@dolgaroo root]# scp .ssh/identity.pub dolgaroo@163.1
80.121.32:.ssh/authorized_keys dolgaroo@163.180.121.32's password:
identity.pub         100% |*****************************|   332       00:00
[root@dolgaroo root]# ssh-agent bash
[root@dolgaroo root]# ssh-add .ssh/identity
Identity added: .ssh/identity (root@dolgaroo)
[root@dolgaroo root]# exit
exit
[root@dolgaroo root]# ssh-agent bash
[root@dolgaroo root]# ssh -l dolgaroo 163.180.121.32
dolgaroo@163.180.121.32's password:
 마지막에서 패스워드를 물어보지 않고 그냥 인증되야 되는걸로 알고 있는데요, 잘 안되네
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