Python 3 script for Ubuntu (And possibly other linux distributions - Tested only for Ubuntu) to display a list of active connections, sorted by number of connections per IP

netstat_list_connections_by_ip.py

#!/usr/bin/env python3
import subprocess


# Takes any domain, ipv4, or ipv6 string and removes a trailing port
def ip_remove_port(par_string):
    loc_count = par_string.count(":")

    if loc_count in [0, 2, 7]:
        # ipv4 or domain with no port (domain.com, 111.222.333.444 - 0 colons
        # ipv6 localhost with no port (::1 - 2 colons)
        # ipv6 with no port (1111:2222:3333:4444:5555:6666:7777:8888 - 7 colons)
        return par_string
    elif loc_count in [1, 3, 8]:
        # ipv4 or domain with port (domain.com:1234, 111.222.333.444:1234 - 1 colon)
        # ipv6 localhost with port (::1:1234 - 3 colons)
        # ipv6 with port (1111:2222:3333:4444:5555:6666:7777:8888:1234 - 8 colors
        loc_split = par_string.split(":")
        del loc_split[-1]
        return ":".join(loc_split)
    else:
        return "INVALID ADDRESS " + par_string


# Used to sort output_list by the count at the beginning of the string
def sort_by_count(par_key):
    loc_split = par_key.split("\t")
    loc_count = loc_split[0]
    return int(loc_count)


# Extract response from netstat
netstat = subprocess.getstatusoutput(
    "netstat -ntu | tail -n +3 | awk '{print $5}' | cut -d \".\" -f1,2,3,4 | sort | uniq -c | sort -nr")
netstat = netstat[1].split("\n")

# Remove port from entries, combine connection counts, store data into a temporary dictionary as {"address": int(count)}
addresses = {}
for par_entry in netstat:
    while '  ' in par_entry:
        par_entry = par_entry.replace('  ', ' ')
    par_entry = par_entry.strip()

    entry = par_entry.split(" ")
    count = entry[0]
    count = int(count)
    address = ip_remove_port(entry[1])

    if address in addresses:
        count = addresses[address] + count

    addresses[address] = count

# Sort entries in a list
output_list = []
for address, count in addresses.items():
    output_list.append(str(count) + "\t" + address)

output_list.sort(key=lambda key: sort_by_count(key), reverse=True)

# Print the list of entries
for output in output_list:
    print(output)