In DOS or cmd line.. Let me back up. Windows NT 4.0, Windows 2000, and Windows XP do not have DOS. They have a command line that looks a hell of a lot like DOS. Windows 95, 98, ME have DOS. For the point of this disscusion DOS and commandline are the same thing.(Even though they really are not)

The netstat DOS help file is shown below


Displays protocol statistics and current TCP/IP network connections.

NETSTAT [-a] [-e] [-n] [-s] [-p proto] [-r] [interval]

-a Displays all connections and listening ports.
-e Displays Ethernet statistics. This may be combined with the -s
-n Displays addresses and port numbers in numerical form.
-p proto Shows connections for the protocol specified by proto; proto
may be TCP or UDP. If used with the -s option to display
per-protocol statistics, proto may be TCP, UDP, or IP.
-r Displays the routing table.
-s Displays per-protocol statistics. By default, statistics are
shown for TCP, UDP and IP; the -p option may be used to specify
a subset of the default.
interval Redisplays selected statistics, pausing interval seconds
between each display. Press CTRL+C to stop redisplaying
statistics. If omitted, netstat will print the current
configuration information once.
The letters you see are known as switches or attributes. Each one dose something different. You can combine them to spit out even more info.
Play with the switches a bit and you will see al kinds of good info.

I think you might find netstat -s useful
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