Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Bash script to list all IPs in prefix

Tags:

I'm trying to create script that I can input a set of prefixes, which will then list all IP addresses within the prefixes (including network/host/broadcast).

An example would be:

./convert-prefix-to-IPs.sh 192.168.0.0/23 203.20.0.0/16
192.168.0.0
192.168.0.1
... 
192.168.0.255
192.168.1.0
.. 
192.168.1.255
203.20.0.0
..
203.20.255.255

There are some python/perl scripts which can do this, but I'm hoping to have a simple bash script, as it may be used on systems without perl/python (yes.. i know.. )

like image 695
user2463938 Avatar asked Jun 07 '13 14:06

user2463938


People also ask

How do I show all active IPv4?

On Windows or macOS type ipconfig or on Linux type ifconfig. Press return. Note down the subnet mask, the default gateway, and your own computer's IPv4 address. Enter the command arp -a to get a list of all other IP addresses active on your network.

What is Sipcalc?

Sipcalc is an advanced command-line IP subnet calculator. It can take multiple forms of input (IPv4/IPv6/interface/hostname) and output a multitude of information about a given subnet. Features include: IPv4. Retrieving of address information from interfaces.

How do I find my IP on bash Linux?

To find out the IP address of Linux/UNIX/*BSD/macOS and Unixish system, you need to use the command called ifconfig on Unix and the ip command or hostname command on Linux. These commands used to configure the kernel-resident network interfaces and display IP address such as 10.8. 0.1 or 192.168. 2.254.


2 Answers

Here is what I use to generate all the IP addresses in a given CIDR block

nmap -sL -n 10.10.64.0/27 | awk '/Nmap scan report/{print $NF}'

From the nmap man page, the flags are:

-sL: List Scan - simply list targets to scan
-n: Never do DNS resolution

Just that simple

The above command outputs this

10.10.64.0
10.10.64.1
10.10.64.2
10.10.64.3
10.10.64.4
10.10.64.5
10.10.64.6
10.10.64.7
10.10.64.8
10.10.64.9
10.10.64.10
10.10.64.11
10.10.64.12
10.10.64.13
10.10.64.14
10.10.64.15
10.10.64.16
10.10.64.17
10.10.64.18
10.10.64.19
10.10.64.20
10.10.64.21
10.10.64.22
10.10.64.23
10.10.64.24
10.10.64.25
10.10.64.26
10.10.64.27
10.10.64.28
10.10.64.29
10.10.64.30
10.10.64.31
like image 116
John Vossler Avatar answered Nov 01 '22 14:11

John Vossler


I too was looking for this solution and found that @scherand script worked great. I also have added to this script to give you more option. Help File below.

THIS SCRIPT WILL EXPAND A CIDR ADDRESS.

SYNOPSIS

./cidr-to-ip.sh [OPTION(only one)] [STRING/FILENAME]

DESCRIPTION

-h Displays this help screen

-f Forces a check for network boundary when given a STRING(s)

-i Will read from an Input file (file should contain one CIDR per line) (no network boundary check)

-b Will do the same as –i but with network boundary check

EXAMPLES

./cidr-to-ip.sh 192.168.0.1/24

./cidr-to-ip.sh 192.168.0.1/24 10.10.0.0/28

./cidr-to-ip.sh -f 192.168.0.0/16

./cidr-to-ip.sh -i inputfile.txt

./cidr-to-ip.sh -b inputfile.txt

#!/bin/bash    

############################
##  Methods
############################   
prefix_to_bit_netmask() {
    prefix=$1;
    shift=$(( 32 - prefix ));

    bitmask=""
    for (( i=0; i < 32; i++ )); do
        num=0
        if [ $i -lt $prefix ]; then
            num=1
        fi

        space=
        if [ $(( i % 8 )) -eq 0 ]; then
            space=" ";
        fi

        bitmask="${bitmask}${space}${num}"
    done
    echo $bitmask
}

bit_netmask_to_wildcard_netmask() {
    bitmask=$1;
    wildcard_mask=
    for octet in $bitmask; do
        wildcard_mask="${wildcard_mask} $(( 255 - 2#$octet ))"
    done
    echo $wildcard_mask;
}

check_net_boundary() {
    net=$1;
    wildcard_mask=$2;
    is_correct=1;
    for (( i = 1; i <= 4; i++ )); do
        net_octet=$(echo $net | cut -d '.' -f $i)
        mask_octet=$(echo $wildcard_mask | cut -d ' ' -f $i)
        if [ $mask_octet -gt 0 ]; then
            if [ $(( $net_octet&$mask_octet )) -ne 0 ]; then
                is_correct=0;
            fi
        fi
    done
    echo $is_correct;
}

#######################
##  MAIN
#######################
OPTIND=1;
getopts "fibh" force;

shift $((OPTIND-1))
if [ $force = 'h' ]; then
    echo ""
    echo -e "THIS SCRIPT WILL EXPAND A CIDR ADDRESS.\n\nSYNOPSIS\n  ./cidr-to-ip.sh [OPTION(only one)] [STRING/FILENAME]\nDESCRIPTION\n -h  Displays this help screen\n -f  Forces a check for network boundary when given a STRING(s)\n    -i  Will read from an Input file (no network boundary check)\n  -b  Will do the same as –i but with network boundary check\n\nEXAMPLES\n    ./cidr-to-ip.sh  192.168.0.1/24\n   ./cidr-to-ip.sh  192.168.0.1/24 10.10.0.0/28\n  ./cidr-to-ip.sh  -f 192.168.0.0/16\n    ./cidr-to-ip.sh  -i inputfile.txt\n ./cidr-to-ip.sh  -b inputfile.txt\n"
    exit
fi

if [ $force = 'i' ] || [ $force = 'b' ]; then

    old_IPS=$IPS
    IPS=$'\n'
    lines=($(cat $1)) # array
    IPS=$old_IPS
        else
            lines=$@
fi

for ip in ${lines[@]}; do
    net=$(echo $ip | cut -d '/' -f 1);
    prefix=$(echo $ip | cut -d '/' -f 2);
    do_processing=1;

    bit_netmask=$(prefix_to_bit_netmask $prefix);

    wildcard_mask=$(bit_netmask_to_wildcard_netmask "$bit_netmask");
    is_net_boundary=$(check_net_boundary $net "$wildcard_mask");

    if [ $force = 'f' ] && [ $is_net_boundary -ne 1 ] || [ $force = 'b' ] && [ $is_net_boundary -ne 1 ] ; then
        read -p "Not a network boundary! Continue anyway (y/N)? " -n 1 -r
        echo    ## move to a new line
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            do_processing=1;
        else
            do_processing=0;
        fi
    fi  

    if [ $do_processing -eq 1 ]; then
        str=
        for (( i = 1; i <= 4; i++ )); do
            range=$(echo $net | cut -d '.' -f $i)
            mask_octet=$(echo $wildcard_mask | cut -d ' ' -f $i)
            if [ $mask_octet -gt 0 ]; then
                range="{$range..$(( $range | $mask_octet ))}";
            fi
            str="${str} $range"
        done
        ips=$(echo $str | sed "s, ,\\.,g"); ## replace spaces with periods, a join...

        eval echo $ips | tr ' ' '\n'
else
exit
    fi

done
like image 26
Kyoungs Avatar answered Nov 01 '22 16:11

Kyoungs