[명령어] nc 명령어

nc 명령어

nc 패키지 설치

yum install -y nc (or yum install nmap-ncat)

yum install -y nc

nc 포트 오픈 확인

nc -z -v [hostname/IP address] [port number]

접속 성공(TCP 53 포트)

nc -zvw10 8.8.8.8 53

$ nc -zvw10 8.8.8.8 53
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 8.8.8.8:53.
Ncat: 0 bytes sent, 0 bytes received in 0.05 seconds.

접속 성공(UDP 53 포트)

nc -zvw10 8.8.8.8 -u 53

$ nc -zvw10 8.8.8.8 -u 53
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 8.8.8.8:53.
Ncat: UDP packet sent successfully
Ncat: 1 bytes sent, 0 bytes received in 2.02 seconds.

접속 실패(TCP 54 포트)

nc -zvw10 8.8.8.8 54

$ nc -zvw10 8.8.8.8 54
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connection timed out.

nc 서버 구성

nc 서버(2.2.2.2서버의 80 포트 오픈)

nc -l 80

NC 서버 구성부터 클라이언트로 접속 테스트까지

[서버] 접속 시 노출할 메시지 작성

vim webserver.txt

$ vim webserver.txt
Hello, world!

[서버] 8080 LISTEN

nc -l -p 8080 < webserver.txt

[클라이언트] 8080 포트로 접속 테스트

nc -vw3 127.0.0.1 8080

$ nc -vw3 127.0.0.1 8080 
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 127.0.0.1:8080.
Hello, world!
^C

 

참고URL

- nmap 명령어 : https://scbyun.com/1182