Thursday, December 31, 2009
Today I studied IS-IS Link-State Packet PDU's in more detail, specifically how it relates to both L1 and L2 links. I'm still a little confused on how pseudo-node works in broadcast networks but I have a feeling IS-IS is rarely if ever used as a routing protocol on a LAN network. It also got me to think about ES's (End-Systems) in a IS-IS Network. Since IS-IS uses an entirely different protocol than IP what host or computer even use IS-IS and CLNS instead of the IP stack? I'm going to have to do a little more digging around here but I suspect that it has something to do with the long history of IS-IS. I also went through my portable command book this evening and went through EIGRP commands and a simple lab using SSH instead of the usual console sessions. I think I'm going to go the security route so I might as well get used to encrypting passwords and locking down routers now! I hope everyone has Happy New Years, I won't be celebrating tonight due to my early shift tomorrow but I hope all my friends and family have fun and be safe tonight! 2010 is going to be a BIG year for me, I'm finally starting to see a shimmer of light at the end of the tunnel for a lot of goals I have set for myself.
Wednesday, December 30, 2009
Well today I spent a lot of time reading and re-reading the IS-IS pages on CLNS NSAP (Network Service Access Points) which is basically the OSI version of an IP address. Since I've been dealing mainly with IPv4 and some IPv6 it's been really hard to grasp the NSAP theory. Nothing like reading the same three pages over and over again until you sorta grasp what they're talking about. I believe that repetition is key to becoming good at anything and this seemed to work pretty well because after that I was able to read the rest of the pages pretty easily. NSAP works very similar to an IP protocol but it reminds me kinda of like NetBIOS for some reason. Tomorrow will be more IS-IS theory, this chapter doesn't have much configuration so may try and lab some other topics in the mean time to keep my CLI skills sharp.
Tuesday, December 29, 2009
Today was a short study session this morning, only about an hour since it was mainly just reading about IS-IS (Intermediate System-Intermediate System). During my reading I'm learning that IS-IS are very similar to OSPF mainly because they were developed around the same time and the developers seemed to be in competition with each other the entire time! OSPF is the more popular protocol today based on being focused on IPv4 entirely to begin with. IS-IS uses a short of open ended protocol standard which leaves it very scalable for future purposes. IS-IS is also not nearly as complex to OSPF thanks to simpler mechanisms for creating routing domains and less LSP's (Link-State Packets) needed to accomplish the same goal. I'll probably do a little more research on the history of this protocol tonight along with lab out a couple of Frame-Relay topics just to keep my mind sharp with configuring routers.
Sunday, December 27, 2009
I'm finally doing with Chapter 5 learning about OSPF and how to tune it specifically to your needs. Next up is a totally new technology for me IS-IS (Intermediate System-to-Intermediate System) Protocol. All I know about it so far is that it's a link-state protocol and word on the street is that it's way simplier than OSPF! I'm betting so since this chapter is only about 60 pages compared to the two 70 page chapters on OSPF. I plan on doing the end of chapter multiple choic answers here shortly or tonight and messing around with som OSPF labs I'm finding on the website http://www.sadikhov.com/forum/
Saturday, December 26, 2009
I polished off the rest of the CCNP theory in the Study Guide book by going through the last few pages regarding Virtual Link connections and OSPF Authentication. You would think Cisco would of made EIGRP authentication configuration similar and as easy as OSPF is. Anyways you set these two protocols up completely different which just adds to the growing list of things I'm going to need to remember for the exam. I'm about at the half way mark in a 700 page book which only took me about a month. I estimated that it would take me around 4-5 months so I'm making real good progress. I ordered the CCNP BSCI Portable Command Guide which should come in handy when I want to get quick study sessions in during the days I work. I plan on ordering the BSCI lab guide and the exam guide once I'm near complete with this book. I can't believe how much in-depth this material is, 4 books for 1 exam for a 4 exam certification. in layman's terms it's going to take me 16 books to get this certification at this rate! In actuality though, this is the hardest out of the 4 so once I knock this one out it should be all down hill from that point. I bet I'll need at least 8-10 books though all together which is a big difference than the 2 I needed for the CCNA Certification. Even the 2 books for the CCNA was a bit overkill for that exam honestly!
Friday, December 25, 2009
I spent this Christmas morning studying and configuring the 3 stub types, Stub Area, Totally Stubby Area, and NSSA (Not So Stubby Area). I'm not going to even ask who came up with those names but the material made since as long as you undertood how it effects the LSA type you receive in that particular area. I also ran into something I NEVER noticed so far in the past 8 months I've been learning about Cisco. If you have two directly connected serial interfaces, you CAN'T ping you're own serial IP address if the other side of the serial link is misconfigured in any way. I spent a better part of 30 minutes troubleshooting this problem and even blaming it on the GNS3 program itself until I did a little research. Even if your serial interface shows up/up, if you can't ping your serial IP it's a good chance there's a misconfiguration on either side of the point-to-point connection. MERRY CHRISTMAS!
Thursday, December 24, 2009
My lab studies today was kinda of all over the place. One of the labs I created was testing out connections to my PC's loopback and watching frames be put on the wire (with Wireshark) to my GNS3 lab. Well some how during the testing of this I lost DNS connectivity with my PC and I couldn't for the life of me figure it out. I didn't realize it was an issue with DNS until I tried connecting to google.com using it's IP address and worked but couldn't by using it's host name. After about an hour of t-shooting my own home network (including replacing a router-switch) a simpl reboot fixed all my issues. Troubleshooting 101 tip...reboot your computer first to see if this resolves your problems! Anyways after that fiasco, I finished my studying today about learning a little bit about the different stub types and configuring a multi-homed OSPF lab dealing with route summarization.
Wednesday, December 23, 2009
I began my studies on chapter 5 in the CCNP BSCI Study Guide book on OSPF this morning. I could tell immediatly that the level of depth ramped up and I'm positive it will remain this way from hear on out. The first 4 chapters seemed more like review to me and I was kind of worried I wasn't studying hard enough because I didn't seem to gain a deeper knowledge really of the material and understood most of the topics before I even read the chapters. This Chapter is really starting to show me why they can consider this a professional certification. I'm going to have to cut off all distractions during my study time (well besides my music) such as TV, Internet, etc. It actually worked out quite well this morning as I was able to read what I needed to and created a decent sized lab in about half the time it usually takes me. I learned about the many LSA types and when they are used today. I finished up today by creating a lab that shows the different LSA types sent based on the routers role. In this lab you'll see a couple of ABR's (Area Border Routers), an ASBR (Autonomous System Border Router), and internal routers in their respective areas.
Sunday, December 20, 2009
This morning I polished off the rest of chapter 4 by completing the end of chapter lab which wasn't to bad. I was able to barely finish as an issue arrived with a customers PIX being down. I will finish up the chapter review questions tonight and prepare to move on to the advance routing section this upcoming week. I also will start going over this network security design book an engineer was able to loan out. It's probably a good idea to double up on the security and CCNP studies, I think CCSP might be my next exam after CCNP of course. I also configured quite a bit of different labs concerning OSPF settings when running over a NBMA network last night and this morning. I'm sure I'll be coming back and brushing over a lot of this material again when it comes closer to test time.
Friday, December 18, 2009
Today I spent the better part of my morning configuring two simple OSPF labs along with reviewing the different show and debug commands. It was mostly review but I did get a better understanding of how the OSPF process works by watching the debug commands take place on the routers them selves. I finished off today by studying about the different OSPF network types which are Broadcast, Point-to-Point, and NBMA (Non-Broadcast Multi Access) Networks. Tomorrow I learn about about the subtleties between the OSPF Adjancies along with learning and configuring a few different types of NBMA setups using Frame-Relay of course.
Thursday, December 17, 2009
Today I started my studying on OSPF in the CCNP BSCI Study Guide book. It was mainly just review of LSDB's, LSA's, and the packets that are used to get OSPF up and running. While most of it was CCNA review material the book did go in-depth regarding the packet types and their function. It also displayed interesting diagrams and analogies to help understand how OSPF builds its Link-State Database (LSDB). You can think of LSDB as a map you're looking at in the mall, and the mall it self being the OSPF network. There are multiple maps placed throughout the mall with the same information regarding where every store is located just the same as each router has the same LSDB in an OSPF network . The only difference between the maps in the mall is the "you are here" dot. The dot determines where you are in the mall and the best path to get to every store within that mall. OSPF functions very similar to this, each router uses the LSDB and it's location in the network to determine the best path to get to every other router within the OSPF network!
Tonight I will be finishing up a few more pages regarding OSPF theory and then tomorrow I hope to jump right into configurations, the fun stuff. The pic I added today shows the current topology of the entire global network, pretty wild stuff!
Sunday, December 13, 2009
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
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
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
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
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!
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:
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
- Minimum path Maximum Transmission Unit (MTU) (though not actually used in the calculation)
Tuesday, December 1, 2009
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.