IPv4 Multicast Addressing
Quick Technical Update VoD
Whether it's a live sporting event, real-time cable TV, a CEO's speech to employees, or simply network management or control information, delivering content using multicast technologies continues to gain popularity.
Before learning IP multicast in depth, it's important to understand IP multicast addressing, the topic of this 12-minute VoD.
This Quick Technical Update VoD covers the following topics:
- Uses for IP multicast technologies
- The format of IPv4 multicast addresses
- The conversion of 32-bit IPv4 multicast addresses to 48-bit MAC-layer multicast addresses
Click the image below to watch the VoD (or right-click it to download the 16-MB file so you can carry it with you on your laptop, smart phone, or tablet).
Did you watch the video? It's very exciting. :-) The most important topic it covers is how to convert an IPv4 multicast address to a MAC address. Here are the steps, summarized.
- The top 9 bits of the Class D IP address are not used, so to start, drop the first octet of the Class D IP address. For example, drop 224 in an address such as 224.0.0.5.
- Also make sure the first bit of the second octet is zero. Convert the octet to hex.
- Use the entire third octet, but covert it to hex.
- Use the entire fourth octet, but covert it to hex.
- Prepend 01:00:5E to give you the final result.
For example, 224.0.0.5 becomes 01:00:5E:00:00:05.
Another example: 233.252.16.1 becomes 01:00:5E:7C:10:01.
Brought to you by Priscilla Oppenheimer.