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.

Sunday, November 29, 2009

RIP Protocol and Floating Static Routes


Today I read up on topics related to the two different RIP versions 1 and 2 which was mostly review for me. There was some good stuff such as using both RIPv1 and RIPv2 on a network which i of course created a lab for. I also went over topics related to classful and classless routing over a network and how routing updates are summarized over Dis-contiguous or over different major classful networks. It was a good read and confirmed my suspicion that you can subnet within a classful network using RIPv1 as long as that subnet number is consistent throughout that network. However the network will still be summarized to a /16 when crossing major network boundaries.

I finished up today by learning about Floating Static Routes which was A LOT simpler then I imagined it to be. A floating static route is primarily used when a dynamic routing protocol fails or when you have a WAN link fail and would like to have an automatic fail-over route say through anISDN/DSL backup connection. A floating static route is configured by setting the administrative distance (AD) on a static route higher than the dynamic protocol (AD). By doing this the static route "floats" above the dynamic protocol since best routes when using mutli protocols uses AD to determine the best protocol to use. By default a static route has an AD of either 0 or 1 depending on the configuration. The higher the AD the less likely it is to be used over another protocol as indicated in the picture above.

Saturday, November 28, 2009

Static Route and ODR Overview


Well today was my first real study session on CCNP, from the get go I could tell there is a higher level understanding needed if I'm going to pass this certification. The BSCI goes a lot deeper into routing than anything I've came across so far and just through the first few pages I already set up a few labs pertaining to the information I was reading. I went through setting up a simple static router network which was easy enough followed by setting up a static default lab which wasn't bad at all either. I then finished up by learning and creating a lab for On-Demand Routing (ODR) which is really a Cisco Prioperty way of setting up a cisco network by using CDP rather than a true Dynamic Routing Protocol or setting up Static Routes. All in all not to bad, I didn't get as much as I wanted done today because I came down with a cold and I'm sitting here hoping it doesn't turn into a fever or the flu. Tomorrow I am going to go over some RIP topics and labs which shouldn't be too bad hopefully but we'll see!

Friday, November 27, 2009

SDM Setup Through GNS3


I spent the past two days trying to setup SDM on a router on GNS3 but after several attempts I wasn't successful. I finally decided to use a real 3600 router at our NOC thinking that it was an issue with the GNS3 IOS's I was using (which it was). Before I began the upgrade I noticed that the router IOS version I was using was 12.2 and I needed at least the 12.4 version so I spent quite a bit of time scavenging cables, tftp software, and even a switch (didn't have a cross-over cable). FInally after I upgraded the IOS I noticed that one of the commands I needed to run on that router wouldn't work (ip http secure-server)! So finally I scratched using the real router idea and went back to square one. I ended up using the more appropriate 12.4 IOS I downloaded on my machine for GNS3 and sure enough everything installed. When I finally went to connect to my router through SDM I ran into one last little snag which was the Java applet itself. I would enter my credentials to log in but not much else would happen. After updating to the latest and greatest version everything came right up! Good experience all around just to at least say I know how to install SDM if needed and know what to look out for in the future.

I started and finsihed what I am sure the shortest and easiest CCNP chapter as well. I went through Chapter 1 which basically goes briefly into network design and some processes to think about and implement when trying to build a completely converged network with data, voice, video, security, and etc. all running on one network. It was a good read but now to get into the meat and potatoes of network engineering finally!