I am finally done. ONT was passed today, and with a pretty good score as well. I am very happy. Now it is time for some relaxing, and get on with my training schedule. I really wish we had a testing center somewhere closer that was actually worth going to.
Labs and review.
I am in the process of reviewing and labbing from the lab portfolio. I need to have the verification commands down, so I can troubleshoot different QoS scenarios. I find it very hard to do much configuration though. Also, the wireless section is kind of hard to get good hands-on experience with since I dont have access to any WCS (Wireless Control System).
Wireless and onto labs.
So I am almost done with the wireless section, but alot of things still needs to click in, especially regarding the security aspect of it all. Some more reading on that is needed next. QoS in wireless is done by basically lowering the back-off time in CSMA/CA for higher priority traffic.
Wred, compression and LFI
I am finishing up on chapters regarding WRED and LFI. WRED is a congestion avoidance mechanism. What that means, is that when congestion occurs, you try and avoid filling up the buffers completely by dropping some packets. Normally the standard queueing for fast interfaces (>E1) is FIFO, with the congestion avoidance of tail dropping.
Congestion management and queues.
So im studying about congestion management, namely the use of queuing and the different discplines of queuing. FIFO = First In First Out. This is a straight forward queue which doesnt take any priority, delay or bandwidth into account. This is the default on Cisco equipment for interfaces > 2.
Voip codecs and bandwidth calculation.
So today I have spent some time reading up on voip codecs, and how to calculate bandwidth requirements for a single call with a certain codec. Take for example. G.711 (PCM), which is uncompressed voice data. Its specification says 64kbps raw data output from the codec.
Nbar is a pretty nifty feature.
So today I watched some material on nbar (Network Based Application Recognition), which is a feature originally used for classification of data, used in QoS to mark packets. It uses very deep packet inspection, to figure out what data is being transfered over the network.
ONT = QoS? – I think so
So, so far ONT seems alot like its brother-acronym QoS. Watched a few videos today, solidifying knowledge from BCMSN about CoS only being for L2 trunk links and ToS/DSCP being for Layer 3. Figured out the DE bit provides a somewhat rudimentary QoS for frame-relay.
ONT – Whats the deal?
I skimmed over the ONT blueprint, and it sure seems like alot of voice. I am not quite sure howcome theres that much voice material on there. It bothers me quite frankly, because I dont find the voice part particularly interesting.
I just passed ISCW. Im really glad this one is over with. But I have ALOT of reviewing for the material in this one, when i finish the rest of the CCNP track. I could especially feel that not having access to the FW and IPS parts really hurt me.
Xmas is over, and so is ipsec.
Okay, Xmas is over and so is new years as Im writing this. Im behind regular postings, I know, which is frustrating. I am done with the preliminary reading and lab work for ISCW, but I dont feel prepared for it at all.
Im studying IPSec VPN’s at the moment. There’s alot of terms, protocols and exchanges taking place, and they all use names thats really hard to tie together with what they are doing 🙂 Isakmp for example, what does that do? well, it stands for Internet Security Association and Key Management Protocol.
So I just started work toward the ISCW. The lab book for this is huge, so I think its going to be alot of lab work, and alot of lookups on Cisco’s doc site for further information. My reason for this thinking is the lack of a self-study guide for the ISCW exam.
Thankfully I passed BCMSN. Thank god. It was driving me nuts. Passed with an 864, which im satisfied with. I am thinking about my study technique for the ISCW. I need to see if I can structure it somewhat better than BCMSN, where I ended up reading some topics over and over again.
Trying some reading.
I am trying to get some reading done, even though its extremely hard when im still sick. However, I only got about 5 chapters left in the examination guide. hopefully I can finish them soon, and do some of the last case studies in the lab book.
Done with the self-study guide for BCMSN.
I now need to do the remaining labs in the lab portfolio. There are especially some case studies that bridge all the knowledge together (or so it looks like, we’ll see). I do know however, that wireless is a huge area in and by itself.
Wireless – A forgotten topic on BCMSN.
I have a sneaking suspecion that I better pay alot of attention towards the wireless section of the BCMSN. It seems like its “out-of-scope” of the BCMSN, but Im quite confident that Cisco will really smack me on it for some reason.
Lack of the right equipment.
Lately I have been in the need of the right equipment for quite a few labs. What I really need is some equipment that is able to do both Dynamic Arp Inspection (DAI) and IP Source Guard (IPSG). The dynamic arp part is supported on 3550’s as far as I can see, but IPSG is not.
Been reading the study guide about L2 security. You can really mess up a whole network very simply, and you can basically take down the whole thing pretty easily if your switches are not configured correctly. There was also alot of things about IP spoofing and ARP spoofing.
The need for redundancy becomes clear…
Well, I broke the spanning-tree topology at work today. It was not one of my proudest moments 🙂 I was playing around with the very delicate portfast command, which states in all its glory: “%Warning: portfast should only be enabled on ports connected to a single
Gateway Redundancy.. Awesome
So im studying redundancy features, especially gateway redundancy features. I think this is some impressing technology. Basically there are three versions, HSRP (cisco proprietary), VRRP (IEEE Standard) and GLBP (cisco proprietary). HSRP was introduced in 1994, and VRRP in 1999, GLBP is alot newer, introduced in 2005.
CEF – A topic in disguise
Been reading about CEF yesterday. It doesnt take up much of the exam blueprint, nor CBT nuggets coverage of it. However, it seems that theres more to this than what meets the eye. I also need to figure out what CEF is doing in routers.
Inter-Vlan connectivity and enhancing switch features.
Today I have spent about 2,5 hours studying different features that enhances the switched network. This includes labbing up BPDU guard, Loop guard, UDLD Aggressive mode, BPDU filtering. Also I find the automatic error recovery feature very interesting. You can set certain causes to put an interface into the errdisabled state.
I have been working my a** off trying to understand STP just fairly well. Its a hard topic, especially with Rapid STP. I have struggled with the synchronisation/proposal/agreement thing. It has helped seeing it on the equipment though. An alternate port can be switched to immediately.
Server has been down, and BSCI is down.
Sorry about the lack of posting/progress reports. Also the server has been down for a while. In the meantime, I’ve passed the BSCI exam with an 833 score. Really got my ass kicked on some topics I didnt expect (IS-IS), and ofcourse multicasting which has turned out to be my arch-enemy.
IS-IS is very confusing..
Well, at least some of it. Adjacencies and how IS’s update other IS’s is the thing that nobody can give me an answer to. According to all the material IS’s maintain adjacencies to all others, but still elect a DIS.
(3) EIGRP – Note taking
Alright, I am done with reading about EIGRP. I am now skimming through the chapter, and taking notes. I have an okay understanding of how EIGRP works, and I am looking forward to the labs to nail out unknowns. I am not 100% convinced about taking notes, or rather doing it in the order im doing (reading first, then skimming and taking notes, then going to the lab).
(3) EIGRP reading – continued
Today, I am continuing reading about EIGRP. My goal for today is to get at least 40 pages of EIGRP reading done. Lots of nitty gritty details such as unequal-load balancing and route authentication. To understand and process the material, 10 pages takes up 30 minutes of reading time.
(3) EIGRP Reading
Chapter 3, EIGRP. Started reading about the inner workings of EIGRP today. EIGRP is an improved distance vector protocol provided by Cisco themselves. It is an improved distance vector protocol, because it passes updates directly to its neighbours. It is more advanced than traditional distance vector protocols, because it supports VLSM and it does not use periodic updates.
(2) Routing principles – BSCI selfstudy
Okay. I will try and document some information regarding my study to attain the BSCI (Building Scalable Cisco Internetworks) exam. This is by many considered the hardest exam on the CCNP track (1 of 4 exams). I will tackle this one first, and then continue forward to the other exams knowing they will be easier.
Long time since last post
Okay, so its been a while since my last post. Been having some issues to deal with, which has taken quite alot of energy. I am going for the CCNP, starting with the BSCI exam. Ive got the books for it, and started studying.