Generate a simple TCP Connection Report

constat.sh

#!/usr/bin/env bash
# constat.sh
# ------------------------------------------------------------------------------
# DESCRIPTION:
#     Generate a TCP Connection Report
#
# USAGE:
#  This script can be run directly, setup as a .bashrc function, or called remotely.
#  Remote Use Example: (Tip: Get url by hitting the [RAW] button for this gist)
#    source <(curl -s <url>)
#    bash <(curl -s <url>)
# ------------------------------------------------------------------------------

function constat() {
    tmpfile='/tmp/connections.out';
    netstat -antu > $tmpfile;
    printf "CONNECTION COUNTS (UDP,TCP):\n";
    printf -- "-----------------\n";
    for i in CLOSE_WAIT CLOSED ESTABLISHED FIN_WAIT_1 FIN_WAIT_2 LISTEN SYN_RECEIVED SYN_SEND TIME_WAIT UDP;
    do
        echo -e "${i}: $(grep -ci ${i} ${tmpfile})";
    done;
    total_local_ports=$(( $(cat /proc/sys/net/ipv4/ip_local_port_range | awk '{print $2}') - $(cat /proc/sys/net/ipv4/ip_local_port_range | awk '{print $1}') ));
    echo -e "\n\e[01;39mLOCAL PORT RANGE:\e[0m $(cat /proc/sys/net/ipv4/ip_local_port_range | tr '\t' '-')";
    echo -e "\e[01;39mTOTAL:\e[0m $total_local_ports";
    echo -e "\e[01;39mIN USE:\e[0m $(grep -c ^ ${tmpfile})";
    echo -e "\e[01;39mAVAILABLE:\e[0m $(( $total_local_ports - $(grep -c ^ ${tmpfile}) ))"
}


constat

Remote Use:
source <(curl -s https://gist.githubusercontent.com/AlexAtkinson/d74df51311c27fb787de0c78ca46aa76/raw/bd24b572dbdfe635b826b54433db4e56f8c8851a/constat.sh)