Sunday, December 13, 2009

CCNP Chapter 3 EIGRP Lab

Today I finished up my EIGRP studies by compelting the end of chapter lab along with Q&A's. The lab wasn't to bad and I was able to get through it in a more timely matter than the last chapters lab due to not having to use 11 routers! By time I went through the lab I already knew how to set most things up due to going through all the examples so it really made the lab a breeze. Next week I begin my OSPF studies which I here is one of the most tested subjects on the exam.

Saturday, December 12, 2009

EIGRP Stub Configuration


Today I finished up the rest of the CCNP theory for EIGRP. I learned more about manipulating DUAL by using specific commands of eigrp stub on remote routers to elimante the need for hub routers to query the remote routers for networks that they do not have to begin with. I also went through the various show and debug commands for EIGRP just to get a feel on what really happens when routers are talking to each other via EIGRP. Tomorrow I'll be finishing up Chapter 3 in the CCNP Study Guide book by completing the provided lab and answering a few questions. Next week I begin in depth OSPF theory, there's two whole chapters on this stuff so I'm thinking it's going to take about 3-4 weeks to get through all the OSPF topics in this book.

Friday, December 11, 2009

EIGRP Queries and SIA's


Today I learned a little more theory behind DUAL and it's process, along with a few ways to manipulate the way DUAL queries are sent. The EIGRP DUAL process is very efficiant and can be very scalable in larger networks but only with proper planning. When there are houndreds of routers in a given network, the convergence time for EIGRP can be much longer and more complex than needed. To eliminate convergence time as much as possible, it is smart to plan networks in such a way that there are no more than 7 hops between two routers on a network. One good way to cut down on convergence time is to summarize networks along with using default routes on remote routers that connect to the core. I also learned a lot how SIA (Stuck-in-Active) works and how it can increase convergence time quite a bit on redundant networks. The next few days I will be finishing up my EIGRP study and will be going through mainly labs since most of the theory is finished for this chapter.

Monday, December 7, 2009

EIGRP Bandwidth and Authentication


Today I spent most of my time learning the EIGRP Bandwidth theory along with authentication. Math isn't one of my most favorite subjects but in order to understand route manipulation you have to understand the mechanics behind it. EIGRP is setup to use only 50% of available bandwidth for it's routing by default. So as the picture shows, you will have to manipulate the EIGRP topology in believing that a link is slower than it really is in cases such as Frame Relay multi-point and point-to-point. I spent the last part of my studying time configuring MD5 authentication between two routers by enabling MD5 on the interface and configuring my key chains on both sides of the routers. I won't have time to study like I want to due too my shift beginning tomorrow but I should be wrapping up my CCNP EIGRP studies next week. It's hard to believe that I'm really working on obtaining such a prestigious certification but I'm focused so i don't ponder to much on it. So far the BSCI is doing a very good job of answering a lot of the questions I had while studying the CCNA.

Sunday, December 6, 2009

EIGRP DUAL and Basic Configuration


Today I spent time learning exactly how DUAL works within EIGRP by reading through the CCNP Study Guide along with creating lab scenarios and watching EIGRP debugs. Seeing it in action through the debugs and reading the study-guide book examples gave me a way better understanding of exactly what's going on when the EIGRP AS topology changes. Using the EIGRP Packets it sends EIGRP Queries, Updates, and Replies when the topology changes. I have a fuller understanding of why this protocol is considered a hybrid protocol .Because it does distant-vector tendencies like split-horizon and hold-down timers while it does link-state tendencies such as using the metrics too determine the best path rather than hop count. I finished up tonight by going through one quick simple lab regarding manual route summarization based off the examples that were provided in the study guide. I've also been practicing setting up IP host translations for telnetting between devices. It's a little bit of a pain setting it up but once you do it's a beautiful thing being able to quickly telnet to the device you want rather than having 10 console screens open!

CCNP EIGRP Theory

Yesterday I spent most of my time in the CCNP Study Guide book learning about EIGRP in a little more detail. Such things as the metric used for calculating routes:
\bigg [ \bigg ( K_1 \cdot \text{Bandwidth} + \frac{K_2 \cdot \text{Bandwidth}}{256-\text{Load}} + K_3 \cdot \text{Delay}                       \bigg )          \cdot \frac {K_5}{K_4 + \text{Reliability}} \bigg ] \cdot 256

EIGRP associates five different metrics with each route:

K1 = Bandwidth modifier

  • Minimum Bandwidth (in kilobits per second)

K2 = Load modifier

  • Load (number in range 1 to 255; 255 being saturated)

K3 = Delay modifier

  • Total Delay (in 10s of microseconds)

K4 = Reliability modifier

  • Reliability (number in range 1 to 255; 255 being the most reliable)

K5 = MTU modifier

I also spent time learning about the neighbor table, topology table, and routing tables EIGRP use to determine the best route or Successor route. I spent time going through the 5 types of packets EIGRP uses for making this routing protocol works. Hello's, Updates, Queries, Replies, and ACK (Acknowledgements) are all used in conjunction to make EIGRP work. Today I'm going to be going through many different EIGRP configuration scenarios along with learning more about the DAUL algorithm.

Tuesday, December 1, 2009

CCNP BSCI Chapter 2 Lab


I spent a total of 4 hours configuring, troubleshooting, and manipulating what has to be the biggest Cisco lab I've worked so far. I used a total of 11 routers, 1 switch, and a connection to the outside world. Following the book instructions I spent a good portion of my time configuring two back bone routers and a Cisco router as a Frame-Relay switch. I implimented a lot of commands I wasn't to familar with including some BGP commands and even some multi-cast commands. Everything some how came up as expected with not to many real hitches. The purpose of this lab was to pretty much bring everything I learned in Chapter 2 together. I had 8 routers that I ended up setting RIPv1, then moved to a default route, then enabled ip classless, enabled RIPv2, and last but not least I practiced scalibility by manually summarizing routes on my edge routers. All in all it was a good learning experience and I'm slowly but surely starting to see my knowledge grow.

I have 7 more chapters in this first book and I'm estimating that it's going to take between 2-3 weeks per chapter. Once I'm done with this book then I'm going to buckle down and prep for the exam by going through the Cisco Exam-guide along with the Lab manual. Hopefully by then I should be prepped enough to take this exam, then repeat this process times 3! As you can see there's a long way to go and a lot of dedication needed for any Cisco certification, especially the high level certs.