Anything Over IP & CCNA.co.za Forum

Anything Over IP & CCNA.co.za Forum » Recent Posts http://ccna.co.za/forum/ CCNA to CCIE discussions Thu, 09 Feb 2012 03:40:53 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://ccna.co.za/forum/search.php Jana van Heerden on "Network Support Engineer position available" http://ccna.co.za/forum/topic.php?id=27#post-38 Tue, 05 Apr 2011 08:47:59 +0000 Jana van Heerden 38@http://ccna.co.za/forum/ I am currently recruiting for Capitec Bank's IT division. We have an exciting opportunity available for a certified CCNA and / or CCNP Network Engineer at our offices in Stellenbosch. Interested candidates can contact me directly at <a href="mailto:janavanheerden@capitecbank.co.za">janavanheerden@capitecbank.co.za</a> vl1111 on "CCNA" http://ccna.co.za/forum/topic.php?id=11#post-36 Thu, 17 Mar 2011 11:14:46 +0000 vl1111 36@http://ccna.co.za/forum/ How Does OSPF Neighbor State Change Q1. What are OSPF packets? What do they do? Answer: There are 5 OSPF packets: Hello: Discover neighbors. DD (Data Description): Exchange LSDB catalog (LSA headers). Request: Ask neighbor to send LSA that I don't have. Update: Send LSA requested by neighbors. Ack: Tell Update sending router that I have received your Update. Q2: What are neighbor states? What do they do? Answer: There are 7 states: Down. Neighbor is gone. E.g. neighbor is down, stops running OSPF, or is just initialized. Init: The node has a one-way relationship with a neighbor. It receives a Hello from the neighbor. 2-way. The node has a bidirectional relationship with a neighbor. It has received a Hello from the neighbor and the Hello's neighbor list contains my name. ExStart. Two neighbors negotiate Master-Slave relationship before exchanging LSA. Exchange: Exchange LSDB catalogs with neighbors and find out which LSA is missing. Loading. Ask a neighbor to send LSAs that I don't have. Full: Two neighbors have the same LSDB. They have the same knowledge of the topology. Note: See the companion simulation to relate how routers change states when receiving packets. Q3. How to groups 9 neighbor into some meaningful stages? Answer. These states can be classified into 4 stages: - Discover neighbors. Down, Init, 2-way. Use Hello. - Determine Master-Slave: ExStart, Exchange. Use DD. - Find out which LSA to exchange: Loading. Use DD, Request. - Synchronize LSDB: Full Adjacency. Use Update, Ack. Q4. What is Master-Slave relationship for neighbors? Answer: When two neighbors are ready to exchange LSA catalogs, they need to use a sequence number to tag LSA catalog exchange. The first job is to decide the sequence number. Two neighbors exchange DD to indicate their Router ID. The one with the higher Router ID wins and chooses a sequence number. Note. In the companion simulation (External link), you can click DD to see its content. Q5. Why neighbors need to use a sequence number to track LSA catalog exchange? Answer: Sequence numbers are used to track LSA catalog transaction sessions. A router may have a large LSA catalog that does fit into one DD packet. This router may have several neighbors to exchange LSA catalog at the same time. Q6. Does OSPF use TCP to provide reliable transmission of LSA? Answer: No. OSPF uses Request-Update-Ack to ensure reliable transmission of LSA. Q7. Why doesn't OSPF use TCP to transfer LSA? Answer: TCP is designed to transmit large chunk of data across a congested network. Its goal is to adapt to network congestion and avoid packet losses due to router queue full. It is costly to set up a TCP sessions. An OSPF router transmits LSA to directly connected neighbors. There is no network congestion is involved between sender and receiver nodes. Using a light weight send-ack reliable transmission method is sufficient. This article is the FAQ of an interactive simulation: OSPF Neighbor state. It visualizes topology, packets, router state changes. It listed under External links. External links for network simulation: 1. OSPF Simulation: Neighbor State (This article): <a href="http://www.visualland.net/view.php?cid=915&protocol=OSPF&title=1.5%20Neighbor%20State&ctype=1" rel="nofollow">http://www.visualland.net/view.php?cid=915&protocol=OSPF&title=1.5%20Neighbor%20State&ctype=1</a> 2. More network protocol simulation: <a href="http://www.visualland.net/" rel="nofollow">http://www.visualland.net/</a> vl1111 on "CCNA" http://ccna.co.za/forum/topic.php?id=11#post-35 Thu, 17 Mar 2011 11:12:33 +0000 vl1111 35@http://ccna.co.za/forum/ OSPF Simulation Tutorial for Beginners (Interactive, Visual) OSPF is a complex protocol. To help beginners grasp abstract its concepts, a different approach is taken -- Visualizing OSPF simulation. This tutorial, OSPF basic, simulates the basic OSPF activities on a simple topology: H1-R1-R2-H2. R1 and R2 are routers. H1 and H2 are hosts. This simulation shows 4 stages: 1) R1 and R2 are not running OSPF. H1 ping H2. It fails. 2) Start OSPF on two routers. R1 and R2 discover each other as neighbors by flooding Hello. 3) R1 and R2 develop Full relationship and synchronize their LSA (Link State Advertisement) database by sending DD, Request, and Update. R1 and R2 refresh their routing tables. H1 and H2 become reachable. 4) H1 pings H2 again. It succeeds this time. Q1. What is OSPF? Answer: OSPF is a link state routing protocol. OSPF routers exchange their Link State Advertisement (OSPF LSA) to learn interface IP addresses from each other. Each router saves its LSAs in its Link State Database (LSDB.) Neighboring nodes synchronize their LSDBs. With consistent LSDBs, OSPF routers are able to calculate shortest paths to reach destinations. Q2. What does OSPF do? Answer: Roughly, OSPF is going through the following stages: 1) OSPF node creates a Router LSA to describe its interface IP addresses. This LSA is the most basic LSA. 2) Routers discover neighbors by flooding Hello. When a pair find each other, they are in 2-way state. 3) Neighbors synchronize their LSDBs in three steps: i. Send DD to get LSDB catalog from each other. ii. Send Request to ask for missing LSAs. iii. Send Update to transmit LSAs requested. When two neighbors have the same LSDB, they are in Full Adjacency state. 4) With the same LSDB, routers have consistent knowledge of the network topology and interface IP addresses. They can calculate routing paths independently and update their routing tables. The collection of routing tables from OSPF routers provides the shortest paths between destinations. Q3. What is Router LSA? Answer: Each OSPF router creates a Router LSA to describe its interfaces' IP addresses. In a very simple OSPF network, only Router LSAs are needed to calculate shortest paths. Q4. What does Router LSA do? Answer: In a simple OSPF network (no LAN, no area), neighboring nodes exchange their Router LSAs and learn how many links its neighbor has, and their interface IP addresses. After neighbor propagation, all OSPF nodes have the same set of Router LSAs in their LSDBs. Now they have the same knowledge of network topology. Q5. How can a router use LSDB to calculate routing paths? Answer: From LSDB, an OSPF node learns the complete topology of the network: the number of routers being connected; Individual router's interfaces and their IP addresses; Interface link costs (OSPF metric). With such detail information, OSPF calculates shortest paths to reach all destinations found in LSDB. For example [a], in the OSPF simulation, R1's LSDB contains two Router LSAs: 1) R1 originated LSA contains two IP addresses: 192.168.1.0/24,192.168.3.0/30. 2) R2 originated LSA contains two IP addresses: 192.168.2.0/24,192.168.3.0/30. After LSDB synchronization, R1 and R2 both have these two LSAs. And they know that R1 and R2 are connected by the link 192.168.3.0. Now R1 can calculate routing path to reach remote destination 192.11.68.2.2 and adds an entry (192.168.2.0/24, S1/0) to its routing table. Note [a]: This article is the FAQ of OSPF simulation. After reading, you can play the interactive simulation listed in External Links. It visualize OSPF work flow with moving packets are changing tables. External links for interactive OSPF simulations: 1. OSPF simulation for beginners (This article): <a href="http://www.visualland.net/view.php?cid=767&protocol=OSPF&title=1.1%20OSPF%20basic&ctype=1" rel="nofollow">http://www.visualland.net/view.php?cid=767&protocol=OSPF&title=1.1%20OSPF%20basic&ctype=1</a> 2. List of additional interactive OSPF simulation (Table of Content): <a href="http://www.visualland.net/protocol.overview.php?p=OSPF&protocol=&title=0.%20OSPF%20Overview&ctype=1" rel="nofollow">http://www.visualland.net/protocol.overview.php?p=OSPF&protocol=&title=0.%20OSPF%20Overview&ctype=1</a> akajee on "Cisco Equpiment" http://ccna.co.za/forum/topic.php?id=25#post-34 Sun, 13 Mar 2011 11:26:46 +0000 akajee 34@http://ccna.co.za/forum/ Hi Guys, I am not sure if the guys will be interested for lab equipment but I have a lot of 87 pieces of network equipment (79 being Cisco) and another 8 mixed (7 packeteers, and a shiva)that I am selling. Perfect for building labs for studying and so on. I need to sell the entire lot. contact akajee at gmail dot com if interested. CISCO3700 AS5400 CISCO CATALYST 3100 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 2900 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3750 CISCO CATALYST 3500 CISCO CATALYST 4000 CISCO CATALYST 6500 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2900 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 3500 CISCO CATALYST 2900 CISCO CATALYST 2900 CISCO CATALYST 3600 CISCO AS 5300 CISCO AS 5300 CISCO CATALYST 6500 Cache engine 2500 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2951 CISCO 2600 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2900 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2948 CISCO CATALYST 3550 CISCO CATALYST 3550 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO CATALYST 2900XL CISCO CATALYST 2950 CISCO 3600 CISCO 2600 CISCO CATALYST 2950 CISCO CATALYST 3550 CISCO 2600 CISCO CATALYST 3548 CISCO 2948G CISCO CATALYST 3550 CISCO CATALYST 3524 CISCO CATALYST 3548 CISCO CATALYST 3550 CISCO CATALYST 3548 CISCO CATALYST 3548 CISCO CATALYST 2950 CISCO CATALYST 2950 CISCO 2600 CISCO 2600 CISCO CATALYST 2950 rozeny2k on "CCNA" http://ccna.co.za/forum/topic.php?id=11#post-19 Sat, 25 Dec 2010 14:55:23 +0000 rozeny2k 19@http://ccna.co.za/forum/ Yes of course you can do it part time,some books like 1.CiscoPress Official Exam Certification Guide (ICND1 and ICND2) by Wendell Odom 2. CiscoPress CCNA Portable Command Guide by Scott Empson 3. Boson Exsim Max questions are extremely useful. Video tutorials from cbt nuggets are aw some Beside all these i found that online study is most beneficial,the platform which helped me a lot is <a href="http://ccnaexam4u.blogspot.com" rel="nofollow">http://ccnaexam4u.blogspot.com</a> Flames86 on "CCNA Jobs" http://ccna.co.za/forum/topic.php?id=12#post-18 Tue, 14 Dec 2010 18:18:05 +0000 Flames86 18@http://ccna.co.za/forum/ I recently completed my CCNA and now I'm job-hunting. I also covered A+ theory before studying for my CCNA but never wrote the exam. Also, I have no working experience in IT. Does anyone know of any good agencies or websites where I can forward my CV to? Flames86 on "CCNA" http://ccna.co.za/forum/topic.php?id=11#post-17 Tue, 14 Dec 2010 18:08:32 +0000 Flames86 17@http://ccna.co.za/forum/ One of the best IT institutions in Joburg is Torque IT in Rivonia. You can do your CCNA there buts its very expensive. There is another option though. If you have internet access and can download whatever you want, then you can easily study everything using resources of the net. Thats how I did it and I passed with 961/1000. There are so many CCNA forums out there with people willing to help. Its like a worldwide classroom. I also suggest downloading the CCNA videos from CBT Nuggets.PS, these videos are like gold! With regard to practicals, you can always just use a simulator like Packet Tracer. It functions just like the real thing. I recently completed my CCNA and now I'm looking for a job in that field. If you want to know anything else about the course you can ask me or just mail me on <a href="mailto:maheshjina@yahoo.com">maheshjina@yahoo.com</a> juliet on "CCNA" http://ccna.co.za/forum/topic.php?id=11#post-16 Fri, 03 Dec 2010 13:33:42 +0000 juliet 16@http://ccna.co.za/forum/ I AM AN INFORMATION TECHNOLOGY ENGINEER,I WISH TO FIND OUT WHICH INSTITUDE IS GOOD TO STUDY CCNA IN JOHANNESBURG?CAN SOME ONE HELP ME PLS. WHEN I CAN START TIS COURSE.CAN I DO IT PART TIME?I NEED TO ATTEND CLASSES FOR THE CCNA AND ALSO DO PRACTICALS FOR IT, louiso on "inquiry" http://ccna.co.za/forum/topic.php?id=10#post-15 Mon, 29 Nov 2010 16:42:21 +0000 louiso 15@http://ccna.co.za/forum/ Any idea of CCNA VOICE training in South Africa . Gauteng province preferably ? louiso on "inquiry" http://ccna.co.za/forum/topic.php?id=10#post-14 Mon, 29 Nov 2010 16:34:41 +0000 louiso 14@http://ccna.co.za/forum/ Any idea of CCNA VOICE training in Gauteng ? Jay on "New version of UCCXD due for release on 5th November 09" http://ccna.co.za/forum/topic.php?id=5#post-9 Mon, 18 Jan 2010 11:30:44 +0000 Jay 9@http://ccna.co.za/forum/ Further update. The new version of the course is now available. I've spent the last month with the new version of the software getting it installed as per spec of the Course Administration Guide, which requires all the software to be installed on VMware (for obvious reasons). The new version of the course is almost identical to version 2, with a few changes to the flow of the course as well as some older technologies been removed from the course. The application itself has not changed hugely, but obviously has under gone a face lift with some of the drop down menus and selection boxes. The first noticeable change of the UCCXD version 3 course itself, is the Lab that is required for use during the course. Each pod of the Lab (hosting a maximum of 8 students each) comprises of... - An Admin Server (Windows 2003, Active Directory, SQL, Exchange) - CUCM7 (Cisco Unified Communication Manager Version 7) which is integrated with LDAP to the Active Directory on the Admin Server - CUCCX7 (Cisco Unified Contact Centre Express 7) integrated into the CUCM7 - MRCP Server, for Text to Speech (TTS), and Voice Recognition. This however is not supplied or made by Cisco, and is required that you contact a 3rd Party company for the software Jay on "New version of UCCXD due for release on 5th November 09" http://ccna.co.za/forum/topic.php?id=5#post-8 Thu, 26 Nov 2009 19:38:23 +0000 Jay 8@http://ccna.co.za/forum/ Just a quick update to the above - Cisco has delayed the release of version 3. Last I heard it was delayed till the end of November, but alas it is already the end of November and still no sign of the new course. I have no doubt we can expect to see it in the new year. Jay on "New version of UCCXD due for release on 5th November 09" http://ccna.co.za/forum/topic.php?id=5#post-7 Wed, 30 Sep 2009 12:06:57 +0000 Jay 7@http://ccna.co.za/forum/ The current version of UCCXD 2.0 is to be replaced with the new UCCXD 3.0 on the 5th November 2009. This new release will cover version 7 of the Unified Contact Center Express (UCCX) product and falls under the alignment of all Unified products moving to version 7's. The new version of the UCCXD exam is also scheduled for release on the 5th of November and is said to have quite a few new questions related to version 7 of the product. The course does not seem to have changed a huge amount, and version 7 has had more of a facelift than anything else. The course has been more streamlined with the inclusion of a few more new features and the removal of outdated features. Jay on "640-802 or 640-822 AND 640-816 ??? (CCNA or ICND1 & 2)" http://ccna.co.za/forum/topic.php?id=4#post-6 Fri, 18 Sep 2009 14:11:48 +0000 Jay 6@http://ccna.co.za/forum/ A question I have been asked many times by delegates in class, “should I write the composite CCNA exam, or should I write the two ICND exams separately?” So firstly let’s have a look at the difference between the exams is: The ‘composite’ CCNA exam with a code currently of 640-802 CCNA comprises of 45 - 55 questions and you are allocated 90 minutes to complete the exam. The exam will test you on topics from both the ICND1 and ICND2 courses and upon passing the exam you will receive CCNA status (Cisco Certified Network Associate). You will NOT however receive CCENT status, however is this really an issue? When you have your CCNP are you still going to be telling people you have your CCNA? The bottom line is, in order to have your CCNP you have to have your CCNA, so the one implies the other. Similarly by having your CCNA you supersede having a CCENT. The positive side to having a CCENT is it adds to the CV candy <img src="http://ccna.co.za/forum/my-plugins/bb-smilies/default/icon_wink.gif" title=";)" class="bb_smilies" /> The other option, is to do both 640-822 ICND1 and 640-816 ICND2 exams. 640-822 ICND1 exam comprises of 40 – 50 questions and 90 minutes to complete the exam. You will be tested on only the concepts and topics covered in the ICND1 course outline and upon passing the exam you will receive CCENT status (Cisco Certified Entry Network Technician). The 640-816 ICND2 exam comprises of 40 – 50 questions and 75 minutes to complete the exam. You are tested on the concepts and topics covered in the ICND2 course outline and upon passing the exam you will receive nothing UNLESS you have already passed the 640-822 exam! Only after completing 640-822 AND 640-816 will you receive your CCNA certification. As an comparison between the two, let’s have a look a couple things Pro’s of doing 640-802: 1/ This exam is cheaper than the 2 exams combined. 2/ You only have to write one exam Con’s of doing 640-802: 1/ You don’t receive CCENT status 2/ From what I’ve noticed, more people pass the 2 exams first time, compared to those that pass the composite first time. 3/ You need to study both ICND1 and ICND2 at the same time to be prepared for the exam. Pro’s of the separate exams: 1/ More people pass the 2 exams independently first time, than those that write the composite exam. 2/ You will receive CCENT and CCNA certifications. 3/ You can focus your studying on each exam separately. Con’s of the separate exams: 1/ Writing the 2 exams independently is more expensive than writing the composite exam. 2/ You have to write 2 exams. Jay on "350-001 Version 3 - CCIE R&S Written" http://ccna.co.za/forum/topic.php?id=3#post-3 Mon, 14 Sep 2009 14:26:16 +0000 Jay 3@http://ccna.co.za/forum/ Last week I sat, and passed, this exam in order to recertify my certifications, so the good news is I can relax for another 2 years <img src="http://ccna.co.za/forum/my-plugins/bb-smilies/default/icon_smile.gif" title=":)" class="bb_smilies" /> What I did notice whilst doing this exam, is that Cisco have changed a couple things in the format. 1/ It's no longer 100 questions, but now between 90 - 110. I was asked 104. 2/ The passing score is no longer 70%, but now based on the same structure as the rest of the exams 300 - 1000, with a passing score of 790. 3/ You can no longer go back. Once you have chosen an answer, that's it! I've heard that this has been around for a while, but the last time I did the CCIE written was 2 years ago, and it wasn't the case then. They have removed all the wireles sections that I saw mentioned on so many forums, but this makes sense considering there is now a CCIE Wireless. The exam is changing to version 4 on the 18th October 2009, as is the Lab exam, so if you need to get this one behind you, rather sooner than later. Good luck <img src="http://ccna.co.za/forum/my-plugins/bb-smilies/default/icon_smile.gif" title=":)" class="bb_smilies" />