Netstat
netstat example
shibu@shibu-laptop:~$ netstat --inet Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 10.154.58.234:1728 auckland.ubuntu.com:www TIME_WAIT tcp 1 1 10.154.58.234:3624 rockhopper.ubuntu.c:www LAST_ACK tcp 1 1 10.154.58.234:4819 forster.canonical.c:www LAST_ACK shibu@shibu-laptop:~$ netstat --inet --listening Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:domain *:* LISTEN tcp 0 0 localhost:3422 *:* LISTEN udp 0 0 *:domain *:* shibu@shibu-laptop:~$ netstat --inet Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 1 1 10.154.58.234:3624 rockhopper.ubuntu.c:www LAST_ACK shibu@shibu-laptop:~$ netstat --inet --all Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:domain *:* LISTEN tcp 0 0 localhost:3422 *:* LISTEN tcp 0 0 10.154.58.234:1141 72.14.253.93:www TIME_WAIT tcp 0 0 10.154.58.234:3098 www.hostmysite.com:www ESTABLISHED tcp 0 0 10.154.58.234:3099 www.hostmysite.com:www ESTABLISHED tcp 0 0 10.154.58.234:3096 www.hostmysite.com:www ESTABLISHED tcp 0 1 10.154.58.234:3100 www.hostmysite.com:www SYN_SENT tcp 0 0 10.154.58.234:3101 www.hostmysite.com:www ESTABLISHED tcp 0 0 10.154.58.234:3094 www.hostmysite.com:www ESTABLISHED tcp 0 0 10.154.58.234:3093 www.hostmysite.com:www ESTABLISHED tcp 0 1 10.154.58.234:2463 rv-in-f97.google.:https SYN_SENT udp 0 0 *:domain *:* shibu@shibu-laptop:~$ shibu@shibu-laptop:~$ netstat --inet --all -p (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 *:domain *:* LISTEN - tcp 0 0 localhost:3422 *:* LISTEN - shibu@shibu-laptop:~$ su - Password: root@shibu-laptop:~# netstat --inet --all -p Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 *:domain *:* LISTEN 3855/dnsmasq tcp 0 0 localhost:3422 *:* LISTEN 3873/hpiod tcp 0 0 10.154.58.234:1744 ti-in-f164.google.c:www ESTABLISHED5148/firefox-bin tcp 0 0 10.154.58.234:2036 cg-in-f103.google.c:www ESTABLISHED5148/firefox-bin tcp 0 0 10.154.58.234:2829 td-in-f104.google.c:www ESTABLISHED5148/firefox-bin udp 0 0 *:domain *:* 3855/dnsmasq root@shibu-laptop:~#@}
netstat - Print network connections, routing tables, interface statisatics, masquerade connections, and multicast memberships
SYNOPSIS
netstat [address_family_options] [--tcp|-t] [--udp|-u] [--raw|-w]
[--listening|-l] [--all|-a] [--numeric|-n] [--numeric-hosts]
[--numeric-ports] [--numeric-users] [--symbolic|-N]
[--extend|-e[--extend|-e]] [--timers|-o] [--program|-p] [--verbose|-v]
[--continuous|-c]
State
ESTABLISHED
The socket has an established connection.
SYN_SENT
The socket is actively attempting to establish a connection.
SYN_RECV
A connection request has been received from the network.
FIN_WAIT1
The socket is closed, and the connection is shutting down.
FIN_WAIT2
Connection is closed, and the socket is waiting for a shutdown
from the remote end.
TIME_WAIT
The socket is waiting after close to handle packets still in the
network.
CLOSE The socket is not being used.
CLOSE_WAIT
The remote end has shut down, waiting for the socket to close.
LAST_ACK
The remote end has shut down, and the socket is closed. Waiting
for acknowledgement.
LISTEN The socket is listening for incoming connections. Such sockets
are not included in the output unless you specify the --listenā
ing (-l) or --all (-a) option.
CLOSING
Both sockets are shut down but we still donāt have all our data
sent.