telnet 대신 방화벽 확인하기 - nc

성공케이스

[goni9071@tistory.com ~]# nc -z -v www.naver.com 80
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 210.89.160.88:80.
Ncat: 0 bytes sent, 0 bytes received in 0.03 seconds.

실패케이스

[goni9071@tistory.comC ~]# nc -z -v www.naver.com 8080
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connection to 210.89.160.88 failed: Connection refused.
Ncat: Trying next address...
Ncat: Connection refused.