The Netstat Command

Displays active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, IPv4 statistics (for the IP, ICMP, TCP, and UDP protocols), and IPv6 statistics (for the IPv6, ICMPv6, TCP over IPv6, and UDP over IPv6 protocols). Used without parameters, netstat displays active TCP connections.

Syntax
netstat [-a] [-e] [-n] [-o] [-p Protocol] [-r] [-s] [Interval]

Switches:
-A Shows the addresses of any associated protocol control blocks.
-a Will show the status of all sockets. Sockets associated with network
server processes are normally not shown.
-I Shows the state of the network interfaces.
-m Prints the network memory usage.
-n Causes netstat to show actual addresses as opposed tohostnames or
network names.
-r Prints the routing table.
-s Tells netstat to show the per protocol statistics.
-t Replaces the queue length information with timer information.

Examples
To display both the Ethernet statistics and the statistics for all protocols, type the following command: netstat -e -s

To display the statistics for only the TCP and UDP protocols, type the following

command: netstat -s -p tcp udp

To display active TCP connections and the process IDs every 5 seconds, type the following command: nbtstat -o 5

To display active TCP connections and the process IDs using numerical form, type the following command: nbtstat -n -o

Posted in: Networking