Monitoring TCP connections easier and faster in SLES

License: GPLv3

Problem:

Parsing <i>netstat</i> output has always been a pain because of the large amount of data that is available. Sometimes I need some information more than others, but I almost always want to quickly see the total number and type of connection I have.

Solution:

For this purpose I use the following command:

netstat -nap | awk '/tcp/ {print $6}'| sort | uniq -c

The output gives me a quick view of how the connections are even comparing them to other servers.

somecoolhost:~ # netstat -nap | awk '/tcp/ {print $6}'| sort | uniq -c
    400 CLOSE_WAIT
   1049 ESTABLISHED
      2 FIN_WAIT1
      8 FIN_WAIT2
     38 LISTEN
    271 TIME_WAIT
somecoolhost:~ # 

This can be supplemented with a more advanced script, put it in a cron job sending the output to a log and creating graphical statistics, etc.

PLUS

Do not forget that we can obtain more complete summary statistics for each protocol with:

netstat -s