많이 사용하는 옵션(netstat --help)
-r, --route display routing table (라이팅 테이블)
-i, --interfaces display interface table(인터페이스 테이블)
-s, --statistics display networking statistics (like SNMP)(네크워크 통계)
-n, --numeric don't resolve names(PORT 넘버)
--numeric-hosts don't resolve host names
--numeric-ports don't resolve port names
--numeric-users don't resolve user names
-p, --programs display PID/Program name for sockets(PID/프로그램 이름)
-l, --listening display listening server sockets(대기중인 서버 소켓)
-a, --all display all sockets (default: connected)(모든 소켓)
#자주 사용하는 netstat
$ netstat -nap : 연결을 대기중인 목록과 프로그램 목록
ubuntu@ubuntu:~$ netstat -nap
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN -
tcp 0 64 192.168.10.47:22 192.168.10.1:49826 ESTABLISHED -
tcp6 0 0 :::22 :::* LISTEN -
tcp6 0 0 ::1:631 :::* LISTEN -
udp 0 0 0.0.0.0:5353 0.0.0.0:* -
udp 0 0 0.0.0.0:49056 0.0.0.0:* -
udp 0 0 127.0.0.53:53 0.0.0.0:* -
udp 0 0 0.0.0.0:68 0.0.0.0:* -
udp 0 0 0.0.0.0:631 0.0.0.0:* -
udp6 0 0 :::5353 :::* -
udp6 0 0 :::53834 :::* -
raw6 0 0 :::58 :::* 7 -
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node PID/Program name Path
unix 2 [ ] DGRAM 26110 - /run/systemd/journal/syslog
unix 24 [ ] DGRAM 26112 - /run/systemd/journal/dev-log
unix 2 [ ACC ] STREAM LISTENING 26116 - /run/systemd/journal/stdout
unix 9 [ ] DGRAM 26118 - /run/systemd/journal/socket
unix 2 [ ] DGRAM 51014 4266/systemd
$ netstat -an | grep PORT : 지정된 PORT가 사용중인지 정보확인
$ netstat -an | grep 22
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 64 192.168.10.47:22 192.168.10.1:49826 ESTABLISHED
tcp6 0 0 :::22 :::* LISTEN
unix 2 [ ACC ] STREAM LISTENING 51022 /run/user/1000/bus
unix 2 [ ACC ] STREAM LISTENING 41722 /tmp/.X11-unix/X1024
unix 2 [ ACC ] STREAM LISTENING 52259 @/tmp/dbus-myKR69iedh
unix 3 [ ] STREAM CONNECTED 62280 @/tmp/.X11-unix/X0
unix 3 [ ] STREAM CONNECTED 55122
unix 3 [ ] STREAM CONNECTED 28922 /run/systemd/journal/stdout
unix 3 [ ] STREAM CONNECTED 52229
unix 3 [ ] STREAM CONNECTED 62279
$ netstat -ntlp : TCP 에서 리스링중인 PORT & PROGRAM 정보
$ netstat -ntlp
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN -
tcp6 0 0 :::22 :::* LISTEN -
tcp6 0 0 ::1:631 :::* LISTEN -