CODEWITHSUNDEEP
javascript
Sreehari
Sreehari

Reputation: 515

How do you check whether the given IP is internal or not

How do you check whether a given IP is internal or not using only javascript?

For example if you are given an IP of 192.168.1.1 the script should validate this and alert if this is an internal or external IP.

Upvotes: 8

Views: 12608

Answers (5)

Schlagmichdoch
Schlagmichdoch

Reputation: 71

To include IPv6 addresses and check any IP address with one function you could use the following:

    var net = require('net') // requires node.js
    ipIsPrivate(ip) {
        if (ip.substring(0,7) === "::ffff:")
            ip = ip.substring(7);

        if (net.isIPv4(ip)) {
            //         10.0.0.0 - 10.255.255.255        ||   172.16.0.0 - 172.31.255.255                          ||    192.168.0.0 - 192.168.255.255
            return  /^(10)\.(.*)\.(.*)\.(.*)$/.test(ip) || /^(172)\.(1[6-9]|2[0-9]|3[0-1])\.(.*)\.(.*)$/.test(ip) || /^(192)\.(168)\.(.*)\.(.*)$/.test(ip)
        }
        
        // else: ip is IPv6
        const firstWord = ip.split(":").find(el => !!el); //get first not empty word
            
        // The original IPv6 Site Local addresses (fec0::/10) are deprecated. Range: fec0 - feff
        if (/^fe[c-f][0-f]$/.test(firstWord))
            return true;

        // These days Unique Local Addresses (ULA) are used in place of Site Local.
        // Range: fc00 - fcff
        else if (/^fc[0-f]{2}$/.test(firstWord))
            return true;
            
        // Range: fd00 - fcff
        else if (/^fd[0-f]{2}$/.test(firstWord))
            return true;

        // Link local addresses (prefixed with fe80) are not routable
        else if (firstWord === "fe80")
            return true;
        
        // Discard Prefix
        else if (firstWord === "100")
            return true;
            
        // Any other IP address is not Unique Local Address (ULA)
        return false;
    }

If the check should include localhost (127.0.0.1, ::ffff:127.0.0.1 and ::1) use:

    var net = require('net') // requires node.js
    ipIsPrivateOrLocalhost(ip) {
        if (ip.substring(0,7) === "::ffff:")
            ip = ip.substring(7);

        if (net.isIPv4(ip)) {
            // check localhost
            if (ip === '127.0.0.1')
                return true;

            //         10.0.0.0 - 10.255.255.255        ||   172.16.0.0 - 172.31.255.255                          ||    192.168.0.0 - 192.168.255.255
            return  /^(10)\.(.*)\.(.*)\.(.*)$/.test(ip) || /^(172)\.(1[6-9]|2[0-9]|3[0-1])\.(.*)\.(.*)$/.test(ip) || /^(192)\.(168)\.(.*)\.(.*)$/.test(ip)
        }
        
        // else: ip is IPv6
        const firstWord = ip.split(":").find(el => !!el); //get first not empty word

        // equivalent of 127.0.0.1 in IPv6
        if (ip === "::1")
            return true;
            
        // The original IPv6 Site Local addresses (fec0::/10) are deprecated. Range: fec0 - feff
        else if (/^fe[c-f][0-f]$/.test(firstWord))
            return true;

        // These days Unique Local Addresses (ULA) are used in place of Site Local.
        // Range: fc00 - fcff
        else if (/^fc[0-f]{2}$/.test(firstWord))
            return true;
            
        // Range: fd00 - fcff
        else if (/^fd[0-f]{2}$/.test(firstWord))
            return true;

        // Link local addresses (prefixed with fe80) are not routable
        else if (firstWord === "fe80")
            return true;
        
        // Discard Prefix
        else if (firstWord === "100")
            return true;
            
        // Any other IP address is not Unique Local Address (ULA)
        return false;
    }

Builds upon Minko Gechev answer and this implementation to check for private IPv6 addresses in C#

Upvotes: 0

Laquio
Laquio

Reputation: 39

Try this one!

  var id = "10.10.10.10";
  if (/^(10)\.(.*)\.(.*)\.(.*)$/.test(id)){
    //10.x.x.x
  }else if (/^(172)\.(1[6-9]|2[0-9]|3[0-1])\.(.*)\.(.*)$/.test(id)){
    //172.16.x.x - 172.31.255.255
  }else if (/^(192)\.(168)\.(.*)\.(.*)$/.test(id)){
    //192.168.x.x
  }else {
    //else
  }

Upvotes: 1

Lukasz Czerwinski
Lukasz Czerwinski

Reputation: 15432

You could use ipaddr.js library and check whether it returns "private":

const ipaddrJs = require('ipaddr.js');
ipaddrJs.parse('192.168.5.1').range()
> 'private'

https://github.com/whitequark/ipaddr.js/blob/master/lib/ipaddr.js

And if you use Node.js, take a look here: https://www.npmjs.com/package/ipaddr.js

Upvotes: 13

Minko Gechev
Minko Gechev

Reputation: 25672

If you mean private just make sure it's in one of the following ranges:

Private IP address ranges

The ranges and the amount of usable IP's are as follows:

10.0.0.0 - 10.255.255.255 Addresses: 16,777,216

172.16.0.0 - 172.31.255.255 Addresses: 1,048,576

192.168.0.0 - 192.168.255.255 Addresses: 65,536

Function like this should help:

function isPrivateIP(ip) {
   var parts = ip.split('.');
   return parts[0] === '10' || 
      (parts[0] === '172' && (parseInt(parts[1], 10) >= 16 && parseInt(parts[1], 10) <= 31)) || 
      (parts[0] === '192' && parts[1] === '168');
}

Upvotes: 19

Florian Margaine
Florian Margaine

Reputation: 60767

Internal IPs are the following:

10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255

Write the correct regexes for them.

/10\.\d+\.\d+\.\d+/
/192\.168\.\d+\.\d+/

I leave it to you to find out the correct regex for the 172.xxx range.

Upvotes: 5

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