ip_discover

#!/bin/bash

# GNU License, Copyright Mark Bishop, 2014
# Purpose: scan the LAN and run nmap on each LAN device for all connected NICs.
# Save, chmod +x, run from terminal (don't double-click)
# Requires nmap, arp-scan, gawk
# The nic variable could be hardcoded by replacing with nic=eth0, etc.

# Find the name of the active LAN network adaptor(s)
nics=$(ip addr show|egrep '^ *inet'|grep brd|awk -- '{ print $7; }')

echo These NICs appear to be connected:
echo $nics
echo 

# Split the connected NICs into an array for iteration
nicArray=(${nics// / })

#Outer loop, iterate through connected NICs
for j in "${nicArray[@]}"
do
echo Currently using adaptor $j
echo 
nic=$j

#collect arp-scan in a variable
output=$(sudo arp-scan -I$nic -l)   

# Populate an array with the ip addresses from the output
ipArr=($(echo "$output" | gawk '$output ~/^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])/ {print $1}'))

# Print out the first field in each record that is an ip address
echo The following LAN devices were detected on $j
for k in ${ipArr[@]}
do
echo $k
done

# List the IP array by elements and nmap each.
echo
echo nmapping each...
for i in "${ipArr[@]}"
do
echo
echo nmaping $i
sudo nmap -sV -O -v -A $(echo $i)
done

done #end outer loop

echo Press enter to exit
read x