388 Words. Plan about 1 minute(s) to read this.
The last day of class was really a half-day, 9am to 12pm. Narbik purposely constructs the class to run 5.5 days, so that the Friday ends up being a full day. He feels that if you try to run the class as a 5 day class only, it ends up really being 4.5 days because people want to get out early to catch a flight, etc.
Narbik covered multicast during that last morning, and then helped folks with labs. He made some important points to allay the agonizing that we CCIE candidates do about multicast:
- Multicast is not as hard as we make it out to be. It’s more an issue of familiarity than complexity. Since most of us don’t manage multicast on our networks, and multicast is a wee bit different than other protocols we’re used to, we tend to get overly excited about it.
- Multicast is probably 4, maybe 5 points on the test. Obviously, we can’t dismiss multicast because of a low point value, but if we keep the perspective that we need to really, really focus on core routing and switching, losing a point or two in the multicast section isn’t the end of the world. OTOH, losing a point or two on RIP or EIGRP could be a little embarrassing.
He did lecture on multicast, describing the addressing scheme, the RPF check, dense mode, sparse mode, and sparse-dense mode. Then he focused on sparse mode, explaining the function of the rendezvous point, and how multicast traffic flows through the tree when a receiver wants to receive traffic, and when the source begins sending traffic. He also dovetailed that process in with what the mroute table looks like at each step along the way, which was hugely helpful to me personally. Finally, he explained the different ways to select an RP (static, auto-rp, BSR), and how to provide for redundant RPs via MSDP.
It was a fast-moving lecture, although some of us slowed Narbik up with questions. :-) One of the good things about Narbik as an instructor is that he watches the students closely to verify that what he’s saying is making sense to everyone. If someone doesn’t get it, he’ll try a different approach until he gets his point across. He’s really thorough in that way.
One more “overview” posting about the bootcamp coming in a while.
Ethan Banks writes & podcasts about IT, new media, and personal tech.
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