Tag: lsof

What process is using this port?

If lsof is installed in your system:

xeon# lsof 2>/dev/null | fgrep :telnet
telnet    18409    alekz    4u  IPv4 0xffffff0e3b19c740        0t0        TCP xeon:52431->10.0.0.1:telnet (UknownState_-2094513781)

xeon# lsof 2>/dev/null | fgrep :8080
firefox-b   699    alekz   52u  IPv4 0xffffff02db1e0780   0t110637        TCP xeon:51567->dmz:8080 (UknownState_-2094513781)
firefox-b   699    alekz   67u  IPv4 0xffffff0e3b0e06c0   0t127870        TCP xeon:47231->dmz:8080 (UknownState_-2094513781)
squid      2778   nobody    8u  IPv4 0xffffff01dc8ce080        0t0        TCP *:8080 (UknownState_-359969560)
squid      2778   nobody   22u  IPv4 0xffffff01dc6d36c0   0t110637        TCP dmz:8080->xeon:51567 (UknownState_-2094513781)
squid      2778   nobody   41u  IPv4 0xffffff01dc8c26c0   0t127870        TCP dmz:8080->xeon:47231 (UknownState_-2094513781)

If lsof is not installed:

  • Run pfiles /proc/* | less
  • Search for port:
    • Press </>
    • Type port: 23
    • Press <Enter>

The result may look like:

18409:  telnet 10.0.0.1
. . .
4: S_IFSOCK mode:0666 dev:318,0 ino:42212 uid:0 gid:0 size:0
O_RDWR|O_NDELAY
SOCK_STREAM
SO_OOBINLINE,SO_SNDBUF(49152),SO_RCVBUF(49640)
sockname: AF_INET 10.0.0.2  port: 52431
peername: AF_INET 10.0.0.1  port: 23
~
~
~