원격 컴퓨터에서 로컬 컴퓨터로 데이터를 복사하는 방법

다음 명령을 사용하여 원격 컴퓨터의 데이터를 내 컴퓨터로 복사하려고 합니다.

-bash-4.1$ scp gouda@csopt5:/home/gouda/bin/fort.20 home/gouda/Desktop

but I got this message and I couldn't copy my file fort.20.
how to solve this problem
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
The RSA host key for csopt5 has changed,
and the key for the corresponding IP address 172.17.4.15
is unchanged. This could either mean that
DNS SPOOFING is happening or the IP address for the host
and its host key have changed at the same time.
Offending key for IP in /etc/ssh/ssh_known_hosts:4
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    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 the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
1b:a0:e7:43:0d:98:a6:42:01:52:9b:af:f9:d6:08:1c.
Please contact your system administrator.
Add correct host key in /home/gouda/.ssh/known_hosts to get rid of this message.
Offending key in /home/gouda/.ssh/known_hosts:3
RSA host key for csopt5 has changed and you have requested strict checking.
Host key verification failed.