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The following is the output of netstat on a Ubuntu machine. Can someone help decrypt the output? I am especially curious what the ::1:43213 connection is.

Also, why are there so many connections from localhost to localhost on both v4 and v6 tcp/udp?????

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0*               LISTEN     
tcp6       0      0 ::1:7337                :::*                    LISTEN     
udp        0      0    *                          
udp6       0      0 ::1:43213               ::1:43213               ESTABLISHED
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You can use netstat -p as root to show the program PID, then ps faux | grep ^<PID>.

A number of the connections you have listed are listening ports, for instance:

tcp        0      0*               LISTEN 

is something listening on port 7337 for connections on localhost. It is not connected to another machine. Port 68 is a DHCP/BOOTP server.

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Also, ps -fup <PID>. The "-p" will restrict the output to the specified PID. – cjc Mar 22 '12 at 1:46

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