netstat
From Initq
Print network connections, routing tables, interface statistics, masquerade con‐nections, and multicast memberships.
Contents |
Flags
- -c continous
- -n numeric
- -t tcp
- -u udp
- -l listening
- -a all
- -p programs
- -o timer
- -s statistics
- -r routing
- -C cache
Stats -sap
Print Stats, excellent for checking for dropped packets.
root@initq:~# netstat -sap Ip: 135072930 total packets received 0 forwarded 0 incoming packets discarded 134730796 incoming packets delivered 162626118 requests sent out root@initq:~# netstat -sap | grep -i drop 4 ICMP packets dropped because they were out-of-window TCPDeferAcceptDrop: 34838
All tcp programs -tap
This flag shows us all tcp programs.
root@initq:~# netstat -tap Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 *:www *:* LISTEN 6150/apache2 tcp 0 0 *:6544 *:* LISTEN 2007/mythbackend tcp 0 0 *:ssh *:* LISTEN 1125/sshd tcp 0 0 localhost.localdoma:ipp *:* LISTEN 31426/cupsd
All tcp programs numeric -nap
root@initq:~# netstat -nap Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 6150/apache2 tcp 0 0 0.0.0.0:6544 0.0.0.0:* LISTEN 2007/mythbackend tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1125/sshd tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 31426/cupsd tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 1832/master tcp 0 0 0.0.0.0:47304 0.0.0.0:* LISTEN 899/rpc.statd tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 1753/mysqld
All tcp and udp
root@initq:~# netstat -tuap Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 *:www *:* LISTEN 6150/apache2 tcp 0 0 *:6544 *:* LISTEN 2007/mythbackend tcp 0 0 *:ssh *:* LISTEN 1125/sshd tcp 0 0 localhost.localdoma:ipp *:* LISTEN 31426/cupsd tcp 0 0 *:smtp *:* LISTEN 1832/master tcp 0 0 *:47304 *:* LISTEN 899/rpc.statd
All listening ports -tulp
root@initq:~# netstat -tulp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 *:www *:* LISTEN 6150/apache2 tcp 0 0 *:6544 *:* LISTEN 2007/mythbackend tcp 0 0 *:ssh *:* LISTEN 1125/sshd tcp 0 0 localhost.localdoma:ipp *:* LISTEN 31426/cupsd tcp 0 0 *:smtp *:* LISTEN 1832/master tcp 0 0 *:47304 *:* LISTEN 899/rpc.statd tcp 0 0 localhost.localdo:mysql *:* LISTEN 1753/mysqld
Live watch -tuc
root@initq:~# netstat -tuc -o 3 Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State Timer tcp 0 0 initq.local:36475 ohnonono.l:microsoft-ds ESTABLISHED off (0.00/0/0) tcp 0 0 adsl-99-54-115-12:46611 baymsg1030113.gate:msnp ESTABLISHED off (0.00/0/0) tcp 0 0 adsl-99-54-115-12:42442 yi-in-f125.:xmpp-client ESTABLISHED off (0.00/0/0)
Live watch with timer
[root@localhost ~]# netstat -tuc -o 3 Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State Timer tcp 0 48 10.0.2.15:ssh 192.168.1.20:59872 ESTABLISHED on (0.22/0/0)
Routing Cache -rnC
root@initq:~# netstat -rnC Kernel IP routing cache Source Destination Gateway Flags MSS Window irtt Iface 119.63.196.97 99.54.115.124 99.54.115.124 l 16436 0 0 lo 99.54.115.124 72.21.91.19 99.54.115.126 1500 0 0 eth0 74.125.227.33 99.54.115.124 99.54.115.124 l 16436 0 0 lo 192.168.1.20 192.168.1.2 192.168.1.2 1500 0 0 eth1 99.54.115.124 74.125.227.39 99.54.115.126 1500 0 0 eth0 192.168.1.10 224.0.0.251 224.0.0.251 ml 16436 0 0 lo 99.54.115.124 216.137.43.11 99.54.115.126 1500 0 0 eth0
Routing table -rn
root@initq:~# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 99.54.115.120 0.0.0.0 255.255.255.248 U 0 0 0 eth0
