Narbik’s Bootcamp - Day 4 (RIPv2 & Multicast)

Narbik started the day with a brief but detailed lecture on RIPv2. If you are like me then you were probably thinking oh RIP is so easy, why even bother? Well there were a few things that I never studied before so this was a great opportunity for me to pick those up. As with BGP, he started RIPv2 by teaching us ways to optimize RIP and how RIP works. Narbik thinks that if we know how a protocol works, then we won’t have any problems making it work. We covered RIP filtering and he also taught us how to get the even and odd subnets by using a simple multiplication method.

Even and Odd subnets?

I asked him if there is an easier way to determine even and odd numbered subnets. The only method I know involves some serious ANDind and XORing. He asked me a question in response to mine. “When calculating subnets, which bits are the odd bits and which ones are even?” That got me thinking. There is ONLY one odd bit out of the 8 bits and that is number 1! So if that bit is turned off aka ZERO, the end result will ALWAYS be even! Wow this actually makes sense. According to him, AND is nothing but multiplication. Let’s test it out

1 x 1 = 1

0 x 1 = 0

0 x 0 = 0

I will type up a detailed post about even and odd numbered subnets later. But basically this is it. Take the network and its subnet. Inverse the subnet and then AND the network with the subnet and the result you get is either 1 or 0 in the last bit.

We also covered hop count, offset-list, summarization, default route, authentication and a few advnaced scneraios.

After this he asked us to complete RIPv2 and EIGRP labs that we completed around 7pm.

Multicast Lecture

I was looking forward to multicast since day one and was very excited to finally learn about multicast. He started with a little background on multicast and then moved on top the two types of multicast. We covered multicast filtering, rpf check, tree construction, Auto-RP, Types of RPs etc. I can post all my notes but that’s way too much typing so I will refrain from doing that. All I know is this was a great lecture but I need to finish these labs so I can better understand the technology.