The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

  • My badges

  • Twitter Updates

  • My Flickr Stream

  • Pages

  • All categories

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 2,482 other followers

Verifying if two hosts are on the same IPv4 network

Posted by jpluimers on 2011/02/17

Recently, I wrote a bunch of code both in C# and Delphi to verify if two hosts are on the same IPv4 network.

Even though the public IPv4 address space is exhausted (IANA recently allocated the final two IPv4 blocks of their primary pool to APNIC, then allocated the five remaning /8 IPv4 blocks to the RIRs, thereby depleting the IPv4 pool), they are still used a lot, especially in private networks.

Over the next couple of weeks, you will see a couple of blog posts explaining:

  • how to get the IPv4 addresses and network masks of network interfaces in your computer
  • how to convert those to and from strings
  • how to convert a host-name to a list of IP addresses
  • how to lookup the current host-name
  • how network masks are related to counting leading/trailing ones and zeros
  • how to compare two IPv4 addresses given they have the same network masks

Those blog posts will have sample code in both Delphi and C#. And there will be unit tests to verify the underlying code.

–jeroen

2 Responses to “Verifying if two hosts are on the same IPv4 network”

  1. KM said

    Look here to be aware how IANA wastes IP ranges and spammers take advantage of it…
    http://www.spamhaus.org/drop/

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

 
%d bloggers like this: