Identificare le porte aperte in Linux

In Linux abbiamo diversi modi per identificare le porte aperte sul nostro sistema.

Sicuramente i due comandi più usato sono ss e lsof.

Vediamo qualche esempio partendi dal primo:

$ sudo ss -tulpn
Netid   State    Recv-Q   Send-Q                           Local Address:Port        Peer Address:Port   Process                                     
udp     UNCONN   0        0                                      0.0.0.0:59607            0.0.0.0:*       users:(("kdeconnectd",pid=1008,fd=17))     
udp     UNCONN   0        0                                            *:60081                  *:*       users:(("kdeconnectd",pid=1008,fd=18))     
udp     UNCONN   0        0           [fe80::cb2f:23a0:9031:759c]%enp2s0:546                 [::]:*       users:(("NetworkManager",pid=532,fd=28))   
udp     UNCONN   0        0                                            *:1716                   *:*       users:(("kdeconnectd",pid=1008,fd=15))     
tcp     LISTEN   0        4096                                 127.0.0.1:631              0.0.0.0:*       users:(("cupsd",pid=589,fd=7))             
tcp     LISTEN   0        4096                                     [::1]:631                 [::]:*       users:(("cupsd",pid=589,fd=6))             
tcp     LISTEN   0        50                                           *:1716                   *:*       users:(("kdeconnectd",pid=1008,fd=16))     
tcp     LISTEN   0        100                                          *:7770                   *:*       users:(("java",pid=140604,fd=60))          
tcp     LISTEN   0        50                          [::ffff:127.0.0.1]:37083                  *:*       users:(("idea",pid=140382,fd=251))         
tcp     LISTEN   0        4096                        [::ffff:127.0.0.1]:44821                  *:*       users:(("idea",pid=140382,fd=244))         
tcp     LISTEN   0        4096                        [::ffff:127.0.0.1]:63342                  *:*       users:(("idea",pid=140382,fd=56))  

Oppure:

$ sudo ss -tulpn | grep :7770
tcp   LISTEN 0      100                                     *:7770             *:*    users:(("java",pid=140604,fd=60)) 

Con lsof:

$ sudo lsof -i :7770
COMMAND    PID   USER FD   TYPE DEVICE SIZE/OFF NODE NAME
java    140604 fermat 60u  IPv6 543901      0t0  TCP *:7770 (LISTEN)

Enjoy!