NMC DOiT Vol.2 Scenario 4 Day 3-2 – Various Section Review + Lots of Doc CD Links


Scenario 4 is completed in 427 minutes (7 hours, 7 minutes). That time was with help from http://cisco.com/univercd and in a few cases from the answer key where I just got completely stuck. The big issue in this scenario was the redistribution with tagging. For me, managing all of the lab requirements for how routes are to be preferred in the routing table, and then designing a redistribution scenario to meet those requirements is Really Hard. I don’t know why, but I’ll get it sorted out with practice. Each time, it’s coming easier, and I am seeing the redistribution issues right off in the scenario. I just don’t know how best to resolve the issues right now. In this particular scenario, I never would have come up with the route tagging scheme that was the answer. Could I do it now that I’ve seen it once? Um…I think so, but I’d need a lot of time to work through it. I am planning to come back and do this lab again, perhaps. At least all the IGP and redistribution to see if I can pull it off.

It was gratifying to find several answers easily in the Cisco documentation. They were straightforward tasks that required knowing where to look to find the syntax and make sure you didn’t miss any steps. Priority queueing was one. No one really uses PQ for congestion management. It’s limited in functionality, and has been replaced by far more capable congestion management methods. I was aware of PQ from prepping for the written test, but did not know the syntax to pull it off. But I was able to drill in via http://cisco.com/univercd -> IOS 12.4 -> Cisco IOS Release 12.4 Configuration Guides -> Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4 -> Part 2: Congestion Management -> Configuring Priority Queueing. Everything I needed to know to meet the scenario requirements was there. I just had to scan through a few paragraphs, and I was off and writing IOS code. My code matched the answer key exactly.

Beyond the other sections I’ve blogged about, the scenario also called for IP SLA using ICMP echo and sending an SNMP trap during an SLA timeout event, security with unicast reverse path forwarding, IPv6 addressing and RIP routing, configuring IPv6 on a Cat3560 (don’t forget your SDM template) using a Layer 3 etherchannel and OSPFv3 using a summary-prefix, 3560 IGMP filtering, and compressing audio streams on a PPP link while supporting more than the default number of channels (ip rtp header-compression, ip rtp header-compression and ip rtp compression-connections commands on either end of the PPP link).

So I’ve had a full day here…planning to start with NetMasterClass.com DOiT v2 scenario 5 on Monday.

This week, I also worked through some of the InternetworkExpert.com advanced technologies on-demand class lectures. I’ve covered lectures on multicast and Catalyst QoS, and some of the class on lab strategy. The material is quite good, lots of insight from the instructors. Their approach is to cover the concepts somewhat quickly, with the assumption that you already have a clue, and then dig into equipment, working through practical examples to demonstrate the lecture concepts. I learn really fast that way, so it’s good for me. I think I actually get multicast RPF now (pretty fundamental to multicast routing), so that should make my multicast routing a bit easier to work through on the scenarios.

By Ethan Banks

Ethan Banks is a podcaster and writer with a BSCS and 20+ years in enterprise IT. He's operated data centers with a special focus on infrastructure — especially networking. He's been a CNE, MCSE, CEH, CCNA, CCNP, CCSP, and CCIE R&S #20655. He's the co-founder of Packet Pushers Interactive, LLC where he creates content for humans in the hot aisle.