Priting all IP addresses from an IP range ssh/bash [duplicate] - bash

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cidr converter using sed or awk
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Closed 6 years ago.
I am trying to print all IPs from an IP address range such as 72.21.206.0/23 in the command line more preferably with a single command.
I have tried several commands with awk & cut in combination but was not able to achieve the desired result.
For example if I have the following in file3:
72.21.110.0/16
72.21.206.0/23
and I would like to extract all IPs from 72.21.206.0/23 and print them in separate lines on the screen. I have only reached this point due to my basic knowledge:
awk -F'/' 'NR==2{print $1+1}' file3
which is supposed to print from my assumptions but it is not:
72.21.206.1
Could you please help please.

Answer 1

If you have nmap available you can just run something like:
nmap -n -sL 72.21.110.0/16
This will produce output along the lines of:
Nmap scan report for 72.21.0.0
Nmap scan report for 72.21.0.1
Nmap scan report for 72.21.0.2
[...]
Nmap scan report for 72.21.255.253
Nmap scan report for 72.21.255.254
Nmap scan report for 72.21.255.255
Nmap done: 65536 IP addresses (0 hosts up) scanned in 33.42 seconds
Answers to this question suggest a solution using ipcalc. And having found that, I guess I'm marking this as a duplicate...
Update
A solution in awk, just for you:
BEGIN {
FS="/"
}
{
split($1, octets, ".");
base=lshift(octets[1], 24) + lshift(octets[2], 16)
+ lshift(octets[3], 8) + octets[4];
max=lshift(1, 32-$2);
for (i=0; i<max; i++) {
addr = base + i;
addr = sprintf("%s.%s.%s.%d", rshift(addr, 24),
rshift(and(addr, 0x00FF0000), 16),
rshift(and(addr, 0x0000FF00), 8),
and(addr, 0xFF))
print addr
}
}
Given input like this:
$ echo 192.168.1.0/28 | awk -f ipranger.awk
You get output like this:
192.168.0.0
192.168.0.1
192.168.0.2
192.168.0.3
192.168.0.4
192.168.0.5
192.168.0.6
192.168.0.7
192.168.0.8
192.168.0.9
192.168.0.10
192.168.0.11
192.168.0.12
192.168.0.13
192.168.0.14
192.168.0.15