Remote host identification has chaged 에러 해결 방안

[ 문제 발생 ]
 : Window에서 Linux 서버로 파일을 보내기 위해 SFTP 전송 프로토콜을 자주 이용 했습니다.
   그런데 Linux 서버를 재설치하고 ( ip는 동일) 접속 시도해보니, 아래와 같은 에러가 발생했습니다.
   보통 이런 경우는 다음과 같은 경우에 발생한다고 합니다.
    1) 서버 호스트 키 변경 : 서버 관리자에 의해 호스트 키가 변경됨
    2) 서버 재설치 또는 IP 변경 : 서버가 재설치되거나 IP 주소가 변경됨
   저는 2) 서버 재설치에 해당합니다.

[ 에러 내역 ]   

D:\VirtualMachine>sftp oracle@172.30.1.21
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:37HPp5QZszcmXeYLzz9rIWpnu/rwDYJdNs4EEzNljIA.
Please contact your system administrator.
Add correct host key in C:\\Users\\i love you/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in C:\\Users\\i love you/.ssh/known_hosts:3
ECDSA host key for 172.30.1.21 has changed and you have requested strict checking.
Host key verification failed.
Connection closed

 

 

[ 해결 방안 ]   
  : 호스트 키 삭제 

D:\VirtualMachine>ssh-keygen -R 172.30.1.21
# Host 172.30.1.21 found: line 3
C:\Users\i love you/.ssh/known_hosts updated.
Original contents retained as C:\Users\i love you/.ssh/known_hosts.old

 

 

[ 재접속 시도 ]
 : 접속 성공 

D:\VirtualMachine>sftp oracle@172.30.1.21
The authenticity of host '172.30.1.21 (172.30.1.21)' can't be established.
ECDSA key fingerprint is SHA256:37HPp5QZszcmXeYLzz9rIWpnu/rwDYJdNs4EEzNljIA.
Are you sure you want to continue connecting (yes/no/[fingerprint])?
Warning: Permanently added '172.30.1.21' (ECDSA) to the list of known hosts.
oracle@172.30.1.21's password:
Connected to 172.30.1.21.
sftp>