Cisco: Simple configuration of IP multicast dense mode

Until now, I did not meet a network engineer to be really “in love” with multicast. Some are considering challenging, interesting, useful but most of the network engineers (I repeat myself, from the persons that I discussed with) are rather preferring do other topics that multicast. If you are curious about my position in regarding multicast, well I’m somewhere in the middle. I consider it challenging, a topic for the future (like IPv6), I MUST know it, but let’s say that is not my strongest topic in networking.

I think that I can share some of my experience here with you, and maybe discuss a little bit on th multicast subject. And since I do not want to enter more complex multicast configuration from the start I said I should take it slow with the easiest one: multicast dense mode configuration. As you know there is also sparse mode configuration which can be configured in a more complex way, and I will do it in next tutorials. For now I only hope that you know what is multicast and words like PIM, IGMP, dense-mode, sparse-mode does not sound like alien descriptions for you. If you are feeling insecure about this topic, please check this link as you might get very good information about IP multicast.

For this tutorial I have a simple point to point router connection (R1 and R2) with a subnet of /24 in between, and each router has an additional host (R1 has the multicast sender connected and R2 has the multicast reveiver connected). Since I have no possibility to test the IP multicast traffic in this configuration, the explanation above is just to have a picture about the environment. I hope that for the multicast sparse mode I will find a way to generate some multicast traffic, when I will write the tutorial somewhere next weeks.

Please see the tutorial by clicking the image below:

Multicast dense mode