Check Current Connections

Project Notes

Check the number of connections/sockets in a given state.
Uses iproute2's ss tool to retrieve connections.

Options:
-s State of connection (def: all)
(established, syn-sent, syn-recv, fin-wait-1, fin-wait-2, time-wait,
closed, close-wait, last-ack, listen, and closing)
-f Apply quoted ss expression filter
e.g. '( dst 192.168.1/24 and dport >= :1024 )'
-p <type> Set protocol or family type (udp/tcp/inet/inet6)
-c Critical threshold as an integer
-w Warning threshold as an integer

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# Example: #
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# 1.) Critical if more than 1000 connections to port 443 are in the TCP ESTABLISHED state.
# $ ./check_connections.sh -s established '( sport = :443 )' -w 800 -c 1000