Script to Find All IP Addresses on a Internal Network

[Nytro]

[h=2]Script to Find All IP Addresses on a Internal Network[/h]Posted by purehate in Code Snippets at 12:56 PM

I was working on a presentation this morning and as I was writing I realized I did not have a quick fast way to make a list of all the internal Ips on a LAN (Local Area network). Many of the tools I use including nmap, nessus and nexpose will accept a list of ips so I decided to whip up a quick dirty shell script to get the job done. I may clean it up in the future but for now it does its job. This is meant to work on Backtrack 4 but in its current state it will work on any Debian based distro. As always with any code found on the internet you use this at your own risk. Also I am sure this can be done better but like I said it was a 10 minute fix.

Here is the script:

Save it as ip_list.sh and give it execute permissions with chmod 755

01    #!/bin/bash
02    # Quick a dirty script to make a list of internal ips on a LAN
03    # Questions, Comments or Death Threats can be sent to crackers@question-defense.com
04    # This is made for Backtrack 4 so every one else is on their own
05     
06    #set some variables
07    subnet=$(echo $2 | cut -f 1 -d .)
08    outfile=$subnet"_ip.list"
09    temp=ip.tmp
10     
11    #Check for the proper arguments
12    if [ -z "$1" ]; then
13        echo usage: $0 interface subnet
14        echo "example: arp-scan eth0 192.168.1.0/24"
15        exit
16    fi
17     
18    if [ -z "$2" ]; then
19        echo usage: $0 interface subnet
20        echo "example: arp-scan eth0 192.168.1.0/24"
21        exit
22    fi
23     
24    #check for arp-scan
25    echo "Checking for arp-scan"
26    dpkg --status arp-scan | grep -q not-installed
27     
28    if [ $? -eq 0 ]; then
29        echo "Downloading arp-scan...."
30        sudo apt-get install arp-scan -y
31        else
32        echo "arp-scan found!"
33        fi
34     
35    #running the scan
36    /usr/bin/arp-scan $1 $2 > $temp 2>/dev/null
37    cat ip.tmp | grep $subnet  | awk {'print $1'} > $outfile
38    rm -rf $temp
39     
40    count=$(wc -l $outfile | awk {'print $1'})
41    echo $count "active ip's found"
42    dir=$(pwd)
43    echo "Your file is named" $outfile "and is located in the" $dir "directory"

Sursa: Script to Find All IP Addresses on a Internal Network