HPR4623: A brief infodump on the Broadcast Address and Routing

HPR4623: A brief infodump on the Broadcast Address and Routing

From Hacker Public Radio by Hacker Public Radio

April 22, 2026

About this episode

JonTheNiceGuy discusses network addresses, focusing on CIDR and the broadcast address in IPv4 networking.

This show has been flagged as Clean by the host. Hello Hacker Public Radio, this is JonTheNiceGuy. On the HPR Community News for January 2025 , Ken, Kevie and Some Guy On The Internet were talking about network addresses. As this was part of my job for several years, I thought I might talk about this for a couple of minutes. All IP Networks now use what we refer to as CIDR based addressing, so you'll often see these expressed as "/24", "/16" and so on. This is "how many '1s' are in the binary representation of the local portion of this network. Windows is one of the last remaining platforms to refer to these as Netmasks, and express them as the four octets in decimal representation of those 1s, so /24 is 24 1s in a row, or 255.255.255.0, /16 is 255.255.0.0 and so on. But what does this have to do with networks and networking? There are two pieces to this, the first is for Broadcasts, or how a node with an IPv4 address asks all the local nodes in an IPv4 network address range how to find other things, and the other is for routing. Let's talk about Broadcasts. Right, so back when IPv4 (or just TCP/IP as we knew it then) was being developed to integrate into operating systems, most…

People in this episode

Hosts: JonTheNiceGuy, Kevie

Topics covered

  • network addressing
  • CIDR
  • broadcast address
  • routing
  • IPv4
  • TCP/IP

Keywords

  • CIDR
  • broadcast address
  • IPv4
  • networking
  • TCP/IP
  • netmasks

Mentioned in this episode

Organizations: Hacker Public Radio

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