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- 10 CCENT, CCNA, CCNP Interview Questions By : M. Aslam
What type of routing protocol maintains neighbors? Answer- Link State. What is the range of values for administrative distance? Answer: 0-255 - 2007 Job Market For Microsoft Certified Systems Engineers By : Caitlina Fuller
The 2007 job market for Microsoft Certified Systems Engineers is hot, however that doesn’t mean that every single certified engineer will find the job they have been dreaming about. The reason why is that most businesses are looking for MCSE employees who also have quite a bit of experience under their belt. That is not good news for those people who have spent a lot of time and money studying for their MCSE and have passed all seven exams with flying colors but who lack the hands on experience most businesses are looking for. Nevertheless the outlook is not so bleak for these newbies. There is lots of work for individuals who have their MCSE certification with no experience. However, it might not be making the high dollars they had anticipated while in MCSE boot camp Atlanta. But, the big dollars will come for these individuals after they have some real experience and have proved that the MCSE bootcamp taught them everything they need to know. - A Brief History Of Cisco Certification Training By : Natalie Aranda
Cisco Systems was founded in 1984 by a married couple named Len Bosack and Sandy Lerner. They were computer engineers employed at Stanford University near San Francisco, California. The name cisco, which was originally spelled using a small c, was taken from San Francisco. It created the first commercially successful multi-protocol router. This was exactly the right product at the right time as it enabled previously incompatible computers to communicate with each other. The cisco router was thus instrumental in the establishment and growth of the internet. The change to the standard Internet Protocol (IP) cut drastically into the need for a multi-protocol router, but by this time the company was well established and able to diversify into other networking system products.
In 1990, just six years after it was founded, the company went public and the name was changed to Cisco Systems. The founders walked away with a nice profit of around 170 million dollars. In the following years, the company continued to grow. Just before the dot com. bubble burst, Cisco Systems was one of the richest companies in the world. Today, the company has managed to stay on the cutting edge of networking systems technology and has retained its position as a leader in the field of Internet technology. - A Brief History Of Mcse Certification By : Caitlina Fuller
The MSCE certification has been around ever since certification for systems engineers was an option. However, it has changed over the years and today MSCE certification is incredibly important in the computing field. Especially for those individuals who want to be paid well for their expertise in Microsoft systems. Individuals who are certified show that they know how to do the job and employers feel more comfortable with certified individuals working on their systems. Of course, those who have a lot of experience working with Microsoft systems may outweigh a newly certified individual simply because experience carries a whole lot of weight. Those individuals who are experienced Microsoft systems engineers and who are also MCSE certified will find they have the most job opportunities. - A word about MCSE, A+ and CCNA Braindump Certification. By : M. Aslam
Braindumps are engaged in is an illegal practice that has seismic effects on all concerned. How is it illegal? Every candidates going for IT certification is required to sign non disclosure agreement not to leak the exam related information. But leaks still happen and it is these the leaks have given birth to braindumps providers who are mushrooming by days. - Before Entering The Exam Room: Comptia A+ Certification Practice Tests By : Natalie Aranda
The Computing Technology Industry Association is the sponsor of the CompTia A+ Certification program. This is considered one of the benchmark certifications in the field of Information Technology (IT). It covers the basic knowledge and skills needed for a successful IT and is recognized by employers the world over as a basic educational standard for this career field. It is only natural that the successful completion of this examination is of utmost importance to an aspiring IT. There are several things that a candidate can do to increase their chances in the examination.
There are study materials available from organizations that are members of the CAQC, the CompTia Approved Quality Curriculum. The CLA, CompTia Learning Alliance, also has training centers where students can have instructor guided training to prepare them for the examinations. There is still one last and important thing that can be done once training is complete, and the candidate feels ready to attempt the examination. This is to take one of the A+ certification practice exams. - Bonne humeur au quotidien By : Philippe Binimi
Comment être et rester de bonne humeur ? Ce n'est certes pas une chose facile. Mais c'est possible. Et tout dépend de vos choix... - Buying a Computer By : Jonathan Hutchinson
It isn't fair, but buying a computer is just plain easier for some than it is for others. Those who've purchased and used a computer in the past already have an idea of what they need in a new computer. But those who are new to the computer world could get lost in the myriad of choices available. - CCENT, CCNA, CCNP, CCIE Interview Questions By : M. Aslam
Interviews are tough; make sure you are fully prepared to pass the CCENT, CCNA, CCNP level interview. This article can be great help for you to pass the interview. - Ccna / Ccnp Home Lab Tutorial: Assembling Your Cisco Home Lab By : Chris Bryant, CCIE #12933
A CCNA or CCNP candidate who wants to be totally prepared for their exams is going to put together a home lab to practice on. With used Cisco routers and switches more affordable and plentiful then ever before, there's really no excuse to not have one!
With the many different models available, there is some understandable confusion among future CCNAs and CCNPs about which routers to buy and which ones to avoid. You can take almost any set of Cisco routers and put together a home lab; part of the learning process is taking what equipment you have available and putting together your own lab! For those of you preparing to start your home lab or add to your existing one, this article will list the routers I use in my Cisco pods. You certainly don't have to have all this equipment, but this will give you some good ideas on how to get started. - Ccna / Ccnp Home Lab Tutorial: The Vlan.dat File By : Chris Bryant, CCIE #12933
CCNA and CCNP candidates who have their own Cisco home labs often email me about an odd situation that occurs when they erase a switch's configuration. Their startup configuration is gone, as they expect, but the VLAN and VTP information is still there!
Sounds strange, doesn't it? Let's look at an example. On SW1, we run show vlan brief and see in this abbreviated output that there are three additional vlans in use: - Ccna / Mcse / Ccnp Certification: Making Failure Work For You By : Chris Bryant, CCIE #12933
Whether you're on the road to the CCNA, CCNP, MCSE, or you're on any other computer certification track, the odds are that sooner or later, you're going to fail an exam. It's happened to almost all of us, yours truly included. What you have to keep in mind in these times is that success is not a straight line. You've probably seen charts showing the growth of an industry or a business -- you know, the ones that go from left to right, and look kind of jagged. The line goes up for a while, then down a bit, then up some more, then down a little.
The key? While every business has its setbacks, the net result is that the line goes up and progress is made. That's how you want your certification pursuit and your career to go as well - upward! - Ccna / Network+ Certification Exam Tutorial: Collision Domains And Switches By : Chris Bryant, CCIE #12933
In the previous Network+ exam tutorial, we talked about how collisions occur when data sent by two hosts on a shared Ethernet segment transmit data at the exact same time. Collisions result in the colliding data being unusable, which means the hosts must retransmit the data - and all this extra activity slows the network down!
Carrier Sense Multiple Access with Collision Detection helps limit the number of collisions, but by dividing one large collision domain into smaller collision domains, we can further reduce or actually eliminate the number of collisions. That's where switches come in! - Ccna Certification Exam Training: Circuit Switching Vs. Packet Switching By : Chris Bryant, CCIE #12933
CCNA certification exam training is all about learning the details, and an important part of your CCNA test prep is knowing the differences between Cisco router and switch technologies that are somewhat similar. Packet switching and circuit switching are both methods of getting packets from "point A" to "point B", but the methods used are very different - and you must know these differences to earn your Cisco CCNA certification.
In my last CCNA training tutorial, I discussed packet switching. In case you missed that article, packet switching is a method of transporting packets from source to destination via different paths; that is, the packets will not necessarily share the same physical path. The packets are put into their proper order at the destination. Packet switching is highly effective, but should not be used for delay-sensitive traffic such as voice or video packets. Not only is Frame Relay a big topic for your CCNA certification exam, it's also an excellent example of a packet-switching technology. - Ccna Certification Exam Training: Do Your Best And Get Some Sleep! By : Chris Bryant, CCIE #12933
CCNA certification is tough enough without you making it tough on yourself. There are a few simple things you can do that will increase your exam day performance greatly. Let's take a look at these simple yet powerful techniques.
First, get plenty of sleep the night before. I've taken certification exams from the CCNA to the CCIE, and I'm always amazed at the number of bleary-eyed test takers that show up at the testing center looking like they're about to fall asleep. Don't cram the night before - if you don't know it by 10 PM the night before the exam, you just don't know it. In the words of Dave Attell, "Get some sleep!" - Ccna Certification Exam Training: Passwords, Cisco Routers, And Network Security By : Chris Bryant, CCIE #12933
CCNA certification is important, and so is securing our network's Cisco routers! To reflect the importance of network security, your CCNA certification exam is likely going to contain a few questions about the various passwords you can set on a Cisco router. Let's take a look at some of those passwords and when to apply them.
If the previous user has logged out of the router properly, you will see a prompt like this when you sit down at the router console: - Ccna Certification Exam Tutorial: Cisco Switching Modes By : Chris Bryant, CCIE #12933
To pass the CCNA exam and earn this important certification, you’ve got to know switching inside and out. While you’re learning all the basic switching theory, make sure to spend some time with the one of three switching modes Cisco routers can use.
Store-and-Forward is exactly what it sounds like. The entire frame will be stored before it is forwarded. This mode allows for the greatest amount of error checking, since a CRC (Cyclical Redundancy Check) is run against the frame before it is forwarded. If the frame contains an error, it is discarded. If there’s no problem with the frame, the frame is then forwarded to its proper destination. - Ccna Certification Training: Configuring Static Routes On A Cisco Router By : Chris Bryant, CCIE #12933
The great thing about CCNA certification training is that the skills you learn will truly come in handy when working with Cisco routers and switches in production networks. That's particularly true of static route configuration. While most networks use dynamic routing protocols such as RIP, EIGRP, and OSPF to build routing tables, static routes still come in handy sometimes - especially if a routing protocol configuration goes awry.
Let's say that you just added a new segment to your network and you've successfully added it to your network's routing tables. Suddenly, on Monday morning, users on that segment can't get to a network resource such as an email server, or they can't get out to the Internet. We all know what it's like to try to fix something while the phone's ringing like crazy. That's when we have to do two things. - Ccna Certification: Three Occasions To Reload Or Reopen A Cisco Router Interface By : Chris Bryant, CCIE #12933
Passing the CCNA certification exam means that you know how to configure and troubleshoot a Cisco router instead of using what I call the "hope method" - you know, "Let's reload the router and hope that takes care of it." The majority of Cisco router configurations take effect without the need for a reload, but every once in a while you just have to reload a router or shut and reopen an interface. Let's take a look at three such scenarios.
The first is when you change an OSPF Router ID from its default. For the new RID to take effect, you must either reload the router or clear the OSPF process, which means that all existing adjacencies will come down. Cisco routers are kind enough to tell you this with the following message after you configure a new RID: "Reload or use "clear ip ospf process" command, for this to take effect". - Ccna Cisco Certification Training Case Study: How Multiple Passwords Affect Router Access By : Chris Bryant, CCIE #12933
Your CCNA certification exam efforts must include practicing with different password types and knowing how to configure them on a Cisco router - but for CCNA exam success and to thrive in real-world networks, you also have to know how to examine a Cisco router configuration and determine the level of network security that is already present. After all, most routers you work with already have passwords set, and it's up to you to determine if those passwords are getting the job done.
Let's start with a telnet password. Telnet passwords are configured on the VTY lines, and no telnet access is enabled on a Cisco router by default. If you saw the following configuration, what would it mean? - Ccna Exam Tutorial: Mac Addressing Formats And Broadcasts By : Chris Bryant, CCIE #12933
Your CCNA exam success depends on your mastery of networking, routing, and switching fundamentals. Those fundamentals have to include knowledge of MAC addresses, so let’s take a close look at Media Access Control addressing.
A typical MAC address looks something like this: - Ccnp / Bcmsn Exam Tutorial: Vlan Trunking Protocol (vtp) By : Chris Bryant, CCIE #12933
Passing the BCMSN exam and getting one step closer to the CCNP certification means learning and noticing details that you were not presented with in your CCNA studies. (Yes, I know – you had more than enough details then, right?) One protocol you’ve got to learn more details about is VTP, which seemed simple enough in your CCNA studies! Part of learning the details is mastering the fundamentals, so in this tutorial we’ll review the basics of VTP.
In show vtp status readouts, the "VTP Operating Mode" is set to "Server" by default. The more familiar term for VTP Operating Mode is simply VTP Mode, and Server is the default. It's through the usage of VTP modes that we can place limits on which switches can delete and create VLANs. - Ccnp / Bsci Exam Tutorial: Route Summarization And The Ospf Null Interface By : Chris Bryant, CCIE #12933
CCNP exam success, particularly on the BSCI exam, demands you understand the details of route summarization. This skill not only requires that you have a comfort level with binary conversions, but you have to know how and where to apply route summarization with each individual protocol.
You also have to know the "side effects" of route summarization. With OSPF, there will actually be an extra interface created at the point of summarization, and this catches a lot of CCNP candidates by surprise. Let's take a look at the null0 interface and how it relates to OSPF summarization. - Ccnp Certification / Bcmsn Exam Tutorial: Getting Started With Hsrp By : Chris Bryant, CCIE #12933
Defined in RFC 2281, HSRP is a Cisco-proprietary protocol in which routers are put into an HSRP router group. Along with dynamic routing protocols and STP, HSRP is considered a high-availability network service, since all three have an almost immediate cutover to a secondary path when the primary path is unavailable.
One of the routers will be selected as the primary ("Active", in HSRP terminology), and that primary will handle the routing while the other routers are in standby, ready to handle the load if the primary router becomes unavailable. In this fashion, HSRP ensures a high network uptime, since it routes IP traffic without relying on a single router. - Ccnp Certification / Bcmsn Exam Tutorial: Qos Service Types By : Chris Bryant, CCIE #12933
To pass the CCNP exams, you’ve got to master Quality of Service, and the first step in doing so is knowing the differences between the different QoS types.
Now this being Cisco, we can't just have one kind of QoS! We've got best-effort delivery, Integrated Services, and Differentiated Services. Let's take a quick look at all three. - Ccnp Certification / Bcmsn Exam Tutorial: Server Load Balancing (slb) By : Chris Bryant, CCIE #12933
When you're working on your BCMSN exam on your way to CCNP certification, you'll read at length about how Cisco routers and multilayer switches can work to provide router redundancy - but there's another helpful service, Server Load Balancing, that does the same for servers. While HSRP, VRRP, and CLBP all represent multiple physical routers to hosts as a single virtual router, SLB represents multiple physical servers to hosts as a single virtual server.
In the following example, three physical servers have been placed into the SRB group ServFarm. They're represented to the hosts as the virtual server 210.1.1.14. - Ccnp Certification / Bsci Exam Tutorial: Eigrp Stuck-in-active Routes By : Chris Bryant, CCIE #12933
Passing the BSCI exam and earning your CCNP is all about knowing the details, and when it comes to EIGRP SIA routes, there are plenty of details to know. A quick check in a search engine for "troubleshoot SIA" will bring up quite a few matches. Troubleshooting SIA routes is very challengin in that there's no one reason they occur.
View the EIGRP topology table with the show ip eigrp topology command, and you'll see a code next to every successor and feasible successor. A popular misconception is that we want these routes to have an "A" next to them - so they're active. That's what we want, right? Active routes sound good, right? - Ccnp Certification / Bsci Exam Tutorial: The Bgp Neighbor Process By : Chris Bryant, CCIE #12933
Like TCP, BGP is connection-oriented. An underlying connection between two BGP speakers is established before any routing information is exchanged. This connection takes place on TCP port 179. As with EIGRP and OSPF, keepalive messages are sent out by the BGP speakers in order to keep this relationship alive.
Once the connection is established, the BGP speakers exchange routes and synchronize their tables. After this initial exchange, a BGP speaker will only send further updates upon a change in the network topology. - Ccnp Certification Bcmsn Exam Tutorial: Mac Address Flooding By : Chris Bryant, CCIE #12933
Network attacks take many forms, and it's important to know how the potential security issues with ARP, DHCP, and MAC addresses. They're innocent looking enough, but each of these common network protocols and addresses can be turned against us. Today, we'll talk about what MAC Address Flooding is, how it can be used against our network, and the best defense against this attack.
A MAC Address Flooding attack is an attempt by a network intruder to overwhelm the switch memory reserved for maintenance of the MAC address table. The intruder generates a large number of frames with different source MAC addresses - all of them invalid. As the switch's MAC address table capabilities are exhausted, valid entries cannot be made - and this results in those valid frames being broadcast instead of unicast. - Cisco / Mcse Exam Study: Creating A Road Map To Success By : Chris Bryant, CCIE #12933
Planning for success on the CCNA, CCNP, and other Cisco exams is much like taking a trip in your car. You've got to plan ahead, accept the occasional detour, and just keep on going until you get there. But what do you do before you get started?
Create a road map - for success. - Cisco / Microsoft Computer Certification: Be Ready For Your Opportunity By : Chris Bryant, CCIE #12933
I was reading The Big Moo: Stop Trying To Be Perfect and Start Being Remarkable this morning, and I’d recommend a copy of this to anyone who wants to improve their career and their future. And that’s all of us, right?
There was one particular line that really stood out to me: Betting on change is always the safest bet available. That describes life perfectly, but it also describes a career in Information Technology perfectly as well. There is no field in the world that has the constant and never-ending changes that IT does. And every single one of us can look at this as a massive opportunity for personal and professional growth. - Cisco Ccna / Ccnp / Bcmsn Exam Review: Trunking And Trunking Protocols By : Chris Bryant, CCIE #12933
To earn your CCNA or CCNP certification, you've got to understand the basics of trunking. This isn't just a CCNA topic - you must have an advanced understanding of trunking and etherchannels to pass the BCMSN exam and earn your CCNP as well. Before we address those advanced topics, though, you need to master the fundamentals!
A trunk allows inter-VLAN traffic to flow between directly connected switches. By default, a trunk port is a member of all VLANs, so traffic for any and all VLANs can travel across this trunk. That includes broadcast traffic! - Cisco Ccna / Ccnp Certification Exam Lab: Frame Relay Subinterfaces And Split Horizon By : Chris Bryant, CCIE #12933
Earning your Cisco CCNA and CCNP is a tough proposition, and part of that is the fact that you quickly learn that there’s usually more than one way to do things with Cisco routers – and while that’s generally a good thing, you better know the ins and outs of all options when it comes to test day and working on production networks. Working with Frame Relay subinterfaces and split horizon is just one such situation.
One reason for the use of subinterfaces is to circumvent the rule of split horizon. You recall from your CCNA studies that split horizon dictates that a route cannot be advertised out the same interface upon which it was learned in the first place. In the following example, R1 is the hub and R2 and R3 are the spokes. All three routers are using their physical interfaces for frame relay connectivity, and they are also running RIPv2 172.12.123.0 /24. Each router is also advertising a loopback interface, using the router number for each octet. - Cisco Ccna / Ccnp Certification Exam Review: Protocol Basics By : Chris Bryant, CCIE #12933
To earn your Cisco CCNA certification and pass the BSCI CCNP exam, you have to know your protocol basics like the back of your hand! To help you review these important concepts, here's a quick look at the basics of RIPv1, RIPv2, IGRP, and EIGRP.
RIPv1: Broadcasts updates every 30 seconds to the address 255.255.255.255. RIPv1 is a classful protocol, and it does not recognize VLSM, nor does it carry subnet masking information in its routing updates. Update contains entire RIP routing table. Uses Bellman-Ford algorithm. Allows equal-cost load-balancing by default. Max hop count is 15. Does not support clear-text or MD5 authentication of routing updates. Updates carry 25 routes maximum. - Cisco Ccna / Ccnp Certification Exam Tutorial: Configuring Ppp Callback By : Chris Bryant, CCIE #12933
You may run into situations where a router in a remote location needs to dial in to a central router, but the toll charges are much higher if the remote router makes the call. This scenario is perfect for PPP Callback, where the callback client places a call to a callback server, authentication takes place, and the server then hangs up on the client! This ensures that the client isn't charged for the call. The server then calls the client back.
In the following example, R2 has been configured as the client and R1 is the callback server. Let's look at both configurations and the unique commands PPP Callback requires. - Cisco Ccna / Ccnp Certification Exam Tutorial: Dialer Watch By : Chris Bryant, CCIE #12933
Dialer Watch is a vital part of your CCNA and CCNP studies, particularly for the BCRAN exam, but it's one of the most misunderstood technologies as well. To help you pass the CCNA and CCNP certification exams, here's a detailed look at Dialer Watch.
Dialer Watch allows you to configure a route or routes as "watched" when the watched route leaves the routing table and there is no other valid route to that specific destination, the ISDN link will come up. In the following example, R1 and R2 are connected by both a Frame Relay cloud over the 172.12.123.0 /24 network and an ISDN cloud using the 172.12.12.0 /24 network. The routers are running OSPF over the Frame cloud, and R1 is advertising its loopback of 1.1.1.1/32 as well as an Ethernet segment, 10.1.1.0/24, via OSPF. R2 has both of these routes in its OSPF table, as shown below. - Cisco Ccna / Ccnp Certification Exam Tutorial: Eigrp And Split Horizon By : Chris Bryant, CCIE #12933
EIGRP is a major topic for your CCNA and CCNP studies, and one basic skill you’ll need to pass your Cisco certification exams is to identify situations where you need to enable or disable split horizon. EIGRP commands tend to be a little different than those used with other protocols, so let’s take a look at how EIGRP and split horizon interoperate.
R1 is our hub router, with R2 and R3 as the spokes. There are no subinterfaces, and each router is advertising a single loopback network using its router number for each octet. R1 will see both R2 and R3’s loopback network, but the spokes will not have a route to the other spoke’s loopback. “show ip route eigrp” verifies this. - Cisco Ccna / Ccnp Certification Exam Tutorial: Floating Static Routes By : Chris Bryant, CCIE #12933
To pass the Cisco CCNA and CCNP certification exams, as well as becoming a world-class networker, you've got to know how and when to use floating static routes. And if you're wondering what makes them "float" -- read on!
In this example, R1 and R2 are running OSPF over a Frame Relay network, 172.12.123.0 /24. They're also connected by a BRI ISDN link, 172.12.12.0 /24. R1 is advertising a loopback network, 1.1.1.1 /32, via OSPF. We want R2 to have a route to that loopback even if the frame goes down - and here, we'll use a floating static route to make that happen. - Cisco Ccna / Ccnp Certification Exam Tutorial: Isdn And Multilink Ppp By : Chris Bryant, CCIE #12933
ISDN is a huge topic on both your Cisco CCNA and BCRAN CCNP exams. While many ISDN topics seem straightforward, it’s the details that make the difference in the exam room and working with ISDN in production networks. Configuring and troubleshooting multilink PPP is just one of the skills you’ll need to pass both of these demanding exams.
With BRI, we've got two B-channels to carry data, and both of them have a 64-kbps capacity. You might think it would be a good idea to have both channels in operation before one reaches capacity, and it is a great idea Problem is, it's not a default behavior of ISDN. The second b-channel will not begin to carry traffic until the first one reaches capacity. - Cisco Ccna / Ccnp Certification Exam Tutorial: Troubleshooting Eigrp By : Chris Bryant, CCIE #12933
Part of earning your CCNA and CCNP - especially passing the difficult CIT exam - is becoming a master network troubleshooter. Today, we'll take a look at troubleshooting EIGRP and spotting common errors.
Most adjacency issues are easily resolved - mistyped IP address, bad wildcard mask in the neighbor statement, mistyped EIGRP AS number, and so forth. You know the AS number has to match, but always double-check that. Next, check the wildcard mask to make sure the correct interfaces are EIGRP-enabled. In the following example, we've configured three loopbacks on R2 and want to advertise all three loopbacks via EIGRP, but R4 only sees one. - Cisco Ccna / Ccnp Certification Exam: Attending A Video Boot Camp By : Chris Bryant, CCIE #12933
When you're studying for the CCNA and CCNP exams, you've got a lot of different choices when it comes to training. One popular choice is choosing one of the many "boot camps" and five-day in-person courses that are out there. I've taught quite a few of these, and while many of them are good, they do have drawbacks.
Of course, one is cost. Many employers are putting the brakes on paying for CCNA and CCNP boot camps, and most candidates can't afford to pay thousands of dollars for such a class. Then you've got travel costs, meals, and having to possibly burn your own vacation time to take the class. Add in time away from your family and boot camps become impractical for many CCNA / CCNP candidates. - Cisco Ccna / Ccnp Certification Exam: Cabling Your Home Lab By : Chris Bryant, CCIE #12933
More CCNA and CCNP candidates than ever before are putting together their own home labs, and there's no better way to learn about Cisco technologies than working with the real thing. Getting the routers and switches is just part of putting together a great CCNA / CCNP home lab, though. You've got to get the right cables to connect the devices, and this is an important part of your education as well. After all, without the right cables, client networks are going to have a hard time working!
For your Cisco home lab, one important cable is the DTE/DCE cable. These cables have two major uses in a home lab. To practice directly connecting Cisco routers via Serial interfaces (an important CCNA skill), you'll need to connect them with a DTE/DCE cable. Second, if you plan on having a Cisco router act as a frame relay switch in your lab, you'll need multiple DTE/DCE cables to do so. (Visit my website's Home Lab Help section for a sample Frame Relay switch configuration.) - Cisco Ccna / Ccnp Certification Exam: Caller Id Screening And Callback By : Chris Bryant, CCIE #12933
As a CCNA and/or CCNP candidate, you've got to be able to spot situations where Cisco router features can save your client money and time. For example, if a spoke router is calling a hub router and the toll charges at the spoke site are higher than that of the hub router, having the hub router hang up initially and then call the spoke router back can save the client money (and make you look good!)
A popular method of doing this is using PPP callback, but as we all know, it's a good idea to know more than one way to do things in Cisco World! A lesser-known but still effective method of callback is Caller ID Screening & Callback. Before we look at the callback feature, though, we need to know what Caller ID Screening is in the first place! - Cisco Ccna / Ccnp Certification Exam: Creating A Study Plan By : Chris Bryant, CCIE #12933
Whether you're just starting to think about passing the CCNA or CCNP exams, or you've been on the certification track for a while, you've got to have a plan for success. If you wanted to drive your car from Florida to California, you'd create a plan to get there. You'd get a map and decide how far you wanted to drive per day, and maybe even make some hotel reservations in advance. You certainly wouldn't get in your car, just drive it randomly down the nearest highway, and hope you ended up in California, would you?
Certainly not. Earning your CCNA certification is the same way. It's not enough to just study a few minutes "when you feel like it", or tell yourself that you'll start studying for the exams "when I get such-and-such done". The perfect time to start on the road to Cisco certification is not tomorrow, and it's not next week. It's today. - Cisco Ccna / Ccnp Certification Exam: Frame Relay Becns And Fecns By : Chris Bryant, CCIE #12933
BECNs and FECNs aren't just important to know for your Cisco CCNA and CCNP certification exams - they're an important part of detecting congestion on a Frame Relay network and allowing the network to dynamically adjust its transmission rate when congestion is encountered.
The Forward Explicit Congestion Notification (FECN, pronounced "feckon") bit is set to zero by default, and will be set to 1 if congestion was experienced by the frame in the direction in which the frame was traveling. A DCE (frame relay switch) will set this bit, and a DTE (router) will receive it, and see that congestion was encountered along the frame's path. - Cisco Ccna / Ccnp Certification Exam: Frame Relay Encapsulation Types By : Chris Bryant, CCIE #12933
When you're studying to pass the Cisco CCNA and CCNP certification exams, you quickly learn that there's always something else to learn. (You'll really pick up on this in your CCIE studies, trust me!) Today we'll take a look at an often-overlooked topic in Frame Relay, the encapsulation type. You don't exactly change this on a daily basis in production networks (not if you want to stay employed, anyway!), but it's an important exam topic that you must be familiar with.
The DCE and DTE must agree on the LMI type, but there's another value that must be agreed upon by the two DTEs serving as the endpoints of the VC. The Frame encapsulation can be left at the default of Cisco (which is Cisco-proprietary), or it can be changed to the industry-standard IETF, as shown below. If a non-Cisco router is the remote endpoint, IETF encapsulation must be used. Note that the default of Cisco isn't listed as an option by IOS Help, so you better know that one by heart! - Cisco Ccna / Ccnp Certification Exam: Same Command, Different Results By : Chris Bryant, CCIE #12933
As a CCNA or CCNP, one thing you've got to get used to is that change is constant. Cisco regularly issues new IOS versions, not to mention the many different kinds of hardware they produce! While it's always nice to have "the latest and the greatest" when it comes to routers, switches, firewalls, etc., we have to be prepared for the fact that not all our clients are going to have that latest and greatest!
For instance, there are still quite a few Catalyst 5000 switches out there humming away, and if you're used to working on IOS-driven switches like the 2950, the same command can have dramatically different results. - Cisco Ccna / Ccnp Certification Exam: Troubleshooting Direct Serial Connections By : Chris Bryant, CCIE #12933
A prime topic of your CCNA and CCNP CIT exams will be connecting Cisco routers directly via their Serial interfaces, and while the configuration is straightforward, there are some vital details and show commands you must know in order to pass the exams and configure this successfully in production and home lab networks. Let's take a look at a sample configuration.
Connecting Cisco routers directly via their Serial interfaces works really well once you get it running - and getting such a connection up and running is easy enough. You can use show controller serial x to find out which endpoint is acting as the DCE, and it's the DCE that must be configured with the clockrate command. - Cisco Ccna / Ccnp Certification: How And Why To Build An Etherchannel By : Chris Bryant, CCIE #12933
CCNA and CCNP candidates are well-versed in Spanning-Tree Protocol, and one of the great things about STP is that it works well with little or no additional configuration. There is one situation where STP works against us just a bit while it prevents switching loops, and that is the situation where two switches have multiple physical connections.
You would think that if you have two separate physical connections between two switches, twice as much data could be sent from one switch to the other than if there was only one connection. STP doesn't allow this by default, however in an effort to prevent switching loops from forming, one of the paths will be blocked. - Cisco Ccna / Ccnp Certification: Introduction To Bgp Attributes By : Chris Bryant, CCIE #12933
BGP is one of the most complex topics you'll study when pursuing your CCNP, if not the most complex. I know from personal experience that when I was earning my CCNP, BGP is the topic that gave me the most trouble at first. One thing I keep reminding today's CCNP candidates about, though, is that no Cisco technology is impossible to understand if you just break it down and understand the basics before you start trying to understand the more complex configurations.
BGP attributes are one such topic. You've got well-known mandatory, well-known discretionary, transitive, and non-transitive. Then you've got each individual BGP attribute to remember, and the order in which BGP considers attributes, and what attributes even are... and a lot more! As with any other Cisco topic, we have to walk before we can run. Let's take a look at what attributes are and what they do in BGP. - Cisco Ccna / Ccnp Certification: Ospf E2 Vs. E1 Routes By : Chris Bryant, CCIE #12933
OSPF is a major topic on both the CCNA and CCNP exams, and it's also the topic that requires the most attention to detail. Where dynamic routing protocols such as RIP and IGRP have only one router type, a look at a Cisco routing table shows several different OSPF route types.
R1#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
In this tutorial, we'll take a look at the difference between two of these route types, E1 and E2.
Route redistribution is the process of taking routes learned via one routing protocol and injecting those routes into another routing domain. (Static and connected routes can also be redistributed.) When a router running OSPF takes routes learned by another routing protocol and makes them available to the other OSPF-enabled routers it's communicating with, that router becomes an Autonomous System Border Router (ASBR).
Let's work with an example where R1 is running both OSPF and RIP. R4 is in the same OSPF domain as R1, and we want R4 to learn the routes that R1 is learning via RIP. This means we have to perform route redistribution on the ASBR. The routes that are being redistributed from RIP into OSPF will appear as E2 routes on R4:
R4#show ip route ospf
O E2 5.1.1.1 [110/20] via 172.34.34.3, 00:33:21, Ethernet0
6.0.0.0/32 is subnetted, 1 subnets - Cisco Ccna / Ccnp Exam Tutorial: Five Debugs You Must Know By : Chris Bryant, CCIE #12933
To pass the BSCI exam and move one step closer to CCNP certification success, you've got to know how and when to use debug commands to troubleshoot and verify network operations. While you should never practice debug commands on a production network, it's important to get some hands-on experience with them and not rely on "router simulators" and books to learn about them.
When it comes to RIP, "debug ip rip" is the primary debug to use. This debug will show you the contents of the routing update packets, and is vital in diagnosing RIP version mismatches and routing update authentication issues. - Cisco Ccna / Ccnp Exam Tutorial: Testing Isdn Links Without Pings By : Chris Bryant, CCIE #12933
To earn your Cisco CCNA and CCNP certifications, you've got to master ISDN - and despite what some people say, there's still a lot of ISDN out there that needs to be supported. And when it comes to troubleshooting ISDN, there's a lot to look at. Is the correct ISDN switchtype configured? Are the dialer map statements correct? What about the dialer-group and dialer-list commands? And that's just the start.
I always say that all troubleshooting starts at Layer 1, the Physical layer of the OSI model. The usual method of troubleshooting ISDN is sending pings across the link, but the connection can be tested without using pings or even before assigning IP addresses to the BRI interfaces! - Cisco Ccna / Ccnp Home Lab Setup: How To Configure Reverse Telnet By : Chris Bryant, CCIE #12933
Occasionally, during your CCNA and CCNP studies, you'll run into a term that just doesn't quite make sense to you. (Okay, more than occasionally!) One such term is "reverse telnet". As a Cisco certification candidate, you know that telnet is simply a protocol that allows you to remotely connect to a networking device such as a router or switch. But what is "reverse telnet", and why is it so important to a Cisco CCNA / CCNP home lab setup?
Where a telnet session is started by a remote user who wants to remotely control a router or switch, a reverse telnet session is started when the host device itself imitates the telnet session. - Cisco Ccna / Ccnp Home Lab Tutorial: Buying And Configuring An Access Server By : Chris Bryant, CCIE #12933
A Cisco access server is generally the last item a CCNA or CCNP candidate has on their mind when they're putting together a home lab. The thinking tends to be that since this router isn't really doing anything in the production part of your practice lab, it's not really important.
Once you have more than two devices in your home lab, though, you'll realize that constantly moving the console cable around from one router to another gets very tiresome. That's what an access server does for a home lab - it allows you to connect your PC to a single device when working in your home lab, with no need to constantly disconnect and reconnect the console cable. The console cable will be connected directly to the access server, and the access server is connected to all the other devices in your home lab. Once you start working with one, you'll wonder how you got along without it! - Cisco Ccna / Ccnp Home Lab Tutorial: Cabling Your Access Server By : Chris Bryant, CCIE #12933
A Cisco home lab is an invaluable study tool when you're preparing for CCNA and CCNP exam success. Once you've gotten a couple of routers and switches, you'll quickly get tired of moving that blue console cable every time you want to configure a different device. The solution to this problem is purchasing and configuring an access server (AS).
For those of you new to access servers, note that these are not white boxes running Microsoft operating systems. These are Cisco routers that allow you to connect to all the routers and switches in your home lab without moving a cable. You can physically or logically connect to the access server and work with all your devices from there. - Cisco Ccna / Ccnp Home Lab Tutorial: Configuring An Access Server By : Chris Bryant, CCIE #12933
As your CCNA / CCNP home lab expands, an access server such as the Cisco 2509 or 2511 is one of the best investments you can make. In this article, we'll look at the basic configuration for an access server and discuss how to connect to the other routers and switches in your pod through the AS.
Here's part of a configuration from one of my access servers: - Cisco Ccna / Ccnp Home Lab Tutorial: Planning Ahead For Ie Study By : Chris Bryant, CCIE #12933
Candidates preparing to pass the CCNP exams are putting together Cisco home labs like never before. With CCNA and CCNP home lab equipment more affordable than ever, candidates have realized the importance of working on real Cisco routers and switches on the way to earning their certifications.
One question I get often from CCNP candidates is goes something like this: "I'm planning on pursuing the CCIE after I get my CCNP. What kind of routers and switches should I buy now in order to use the same equipment in my CCIE home lab?" - Cisco Ccna / Ccnp Home Lab Tutorial: Routing On A Frame Relay Switch By : Chris Bryant, CCIE #12933
When you're preparing for CCNA and CCNP exam success, the best investment you can make is to put together your own home lab. There is no better way to learn Cisco technologies and prepare for the CCNA, BSCI, BCMSN, CIT, and other exams than by working with the many protocols and services you'll need to master in order to pass the exams.
One of the most popular articles I've written over the few years dealt with buying and configuring a Cisco router as a frame relay switch. That article is still available on many websites (including my own), but I want to remind you that just because you configure a router as a frame relay switch, that doesn't mean you can't use it as a home lab router, too! - Cisco Ccna / Ccnp Home Lab Tutorial: Starting Over By : Chris Bryant, CCIE #12933
When you're preparing for success on your CCNA or CCNP certification exams, sooner or later you're going to want to start totally from scratch on your Cisco routers and switches. It's easy enough to type "write erase" and "reload", but there are a few details you have to watch if you want your home lab or rack rental devices to act as though they just came out of the box.
The first step is indeed to run the command write erase, and then reload the router. You're going to be prompted with a question before the reload starts, though, and you have to give the right answer .... or your configuration will still be there when you reload! - Cisco Ccna / Ccnp Home Lab Tutorial: The (many) Cable Types And Their Purposes By : Chris Bryant, CCIE #12933
One of the most common questions I get from CCNA and CCNP candidates who are setting up their own home labs is "What cables will I need?" The answer is "It depends." As you know from your exam studies, the physical layout of your lab is what determines the cables you'll need. Let's take a look at the most common home lab cable types and when you will need them.
Straight-through cables have quite a few uses in a CCNA / CCNP home lab. You'll need them to connect a switch port to an AUI port on a router (and you'll need a transceiver for that as well). If you have an ISDN simulator, straight-through cables can be used to connect a router's BRI port to the simulator. - Cisco Ccna / Ccnp Home Lab Tutorial: The 2501 Router By : Chris Bryant, CCIE #12933
To be truly prepared for your CCNA and CCNP exams, you need real hands-on experience with real Cisco routers and switches. However, a production network is a really bad place to practice your configurations, but an excellent way to get fired and/or sued. The key to becoming a true CCNA and CCNP is assembling your own Cisco home lab.
You don't have to spend a lot of money to do so; used Cisco equipment is cheaper than ever. It's robust as well - I've bought literally hundreds of used routers and switches over the years and have had very few problems. I owe much of my skill to practicing configurations and troubleshooting in my own home lab. - Cisco Ccna / Ccnp Home Lab Tutorial: The 2503 Router By : Chris Bryant, CCIE #12933
I know from experience that part of the excitement and anxiety of putting together your own CCNA / CCNP home lab is deciding what to buy! While you can make a workable home lab out of almost any combination of Cisco routers and switches, some routers are better suited for home lab work than others because they can fill multiple roles.
When you buy CCNA or CCNP "lab kits" - bundles of routers and switches - you can get a little confused about whether you're getting a good deal. One router I get asked about quite a bit is the 2503. - Cisco Ccna / Ccnp Home Lab Tutorial: The 2520 Router By : Chris Bryant, CCIE #12933
I hear from CCNA and CCNP candidates every day, and the most common question is "What routers and switches should I buy for my home lab?" There is no one right answer to this question, since every test candidate has a different budget. There are also CCNA candidates who want to go on to the CCNP and want to know what routers and switches are best for future study. Again, there's no one right answer, but there are routers that fit every budget and every study plan - and the Cisco 2520 router is the king of home study labs.
The 2520 has four serial ports, one ethernet port, and a BRI port. You can use a 2520 as a frame relay switch, and still have ports to spare to practice routing protocols and directly connected serial interfaces. I know ISDN home simulators are still expensive if bought new, but you can get a used one on eBay and go from there. Even if you choose not to buy an ISDN simulator now, the 2520 gives you that opportunity for future home lab growth - and "planning for future growth" is important when it comes to your home lab as well as production networks! - Cisco Ccna / Ccnp Home Lab Tutorial: Using 2520 Routers By : Chris Bryant, CCIE #12933
I know from experience that part of the excitement and anxiety of putting together your own CCNA / CCNP home lab is deciding what to buy! While you can make a workable home lab out of almost any combination of Cisco routers and switches, some routers are better suited for home lab work than others because they can fill multiple roles.
My personal favorite is the Cisco 2520. This router has four serial interfaces, making it an ideal frame relay switch. Don't forget that just because you're using a router as a frame switch, you can still use its routing capabilities. One setup I use is to use three of the four serial interfaces for frame switching and the fourth interface as a point-to-point network with another router. All you need is some DTE/DCE cables and you're all set. - Cisco Ccna / Ccnp Home Lab: Why You Need An Isdn Simulator By : Chris Bryant, CCIE #12933
ISDN is a vital topic for today's CCNA and CCNP candidates, especially for the ICND and Intro exams - you've got to know ISDN inside and out to pass those exams. Naturally you want to include it in your home lab. What many candidates don't realize is that you can't connect two Cisco routers directly via their Basic Rate Interface (BRI) interfaces you've got to have another device between them called an ISDN simulator.
An ISDN simulator is not one of those software programs pretending to be routers ("router simulators") this is a piece of hardware that acts as the telephone company in your home lab. Older simulators come with preprogrammed phone numbers and SPIDs, where newer ones let you program the phone numbers you want to use. Either way, an ISDN simulator is great for your CCNA/CCNP home lab, because you can practice dial scenarios that actually work. And you get to troubleshoot the ones that don't, which is also important to learn! ) - Cisco Ccna / Ccnp Home Labs: Developing Troubleshooting Skills By : Chris Bryant, CCIE #12933
CCNA / CCNP candidates are going to be drilled by Cisco when it comes to troubleshooting questions. You're going to have to be able to analyze configurations to see what the problem is (and if there is a problem in the first place), determine the meaning of different debug outputs, and show the ability not just to configure a router or switch, but troubleshoot one.
That's just as it should be, because CCNAs and CCNPs will find themselves doing a lot of troubleshooting in their careers. Troubleshooting isn't something that can just be learned from a book; you've got to have some experience working with routers and switches. The only real way to learn how to troubleshoot is to develop that ability while working on live equipment. - Cisco Ccna / Ccnp Tutorial: Home Lab Assembly Case Study By : Chris Bryant, CCIE #12933
Part of your CCNA / CCNP education is deciding what network topology to use when you're putting together your home lab. Some of you are starting with one or two routers or switches, while others are starting with more. A customer recently sent me a list of his Cisco routers and switches that he has available for a home lab and asked for my help in coming up with the best way to use them.
There is no "right" or "wrong" answer to this question; again, part of the learning process is configuring and reconfiguring the physical topology of your lab. Let's look at the routers and switches he has available, including the interfaces on each, and come up with one possible CCNA / CCNP home lab setup. - Cisco Ccna And Ccnp Bcran Exam Training: Frame Relay Pvc, Svc, Dlci, And Map Statements By : Chris Bryant, CCIE #12933
In today's CCNP certification tutorial, we'll concentrate on the BCRAN exam and Frame Relay PVCs, SVC, and DLCIs in particular.
There are actually two kinds of virtual circuits - Permanent Virtual Circuits (PVCs) and Switched Virtual Circuits (SVCs). An SVC doesn't have anything to do with an L2 switch - it's a VC that is built only under predefined circumstances, similar to an ISDN connection that is only built when interesting traffic hits the line. SVCs go through a basic four-step process, and it's a lot like ISDN: - Cisco Ccna Certification Exam Case Study: Frame Relay, Pings, And Routing Protocols By : Chris Bryant, CCIE #12933
Cisco CCNA certification training includes troubleshooting your own work and that of others. The best CCNA training you can do is indeed troubleshooting your own Cisco router and switch configurations - as I'm always telling my students, "I can guarantee that any error you make has been made before, and you'll probably see it again one day." One such common error involves two very important Cisco CCNA certification topics - Frame Relay and routing protocols.
A student was working on her Cisco CCNA exam home lab and came up with an interesting problem. He set Frame Relay up in a hub-and-spoke configuration with R1 as the hub and R2 and R3 as the spokes. He wrote the following frame map statements: - Cisco Ccna Certification Exam Training: What Is Packet Switching? By : Chris Bryant, CCIE #12933
Cisco CCNA certification exam training means you've got to learn a lot of new terms, and some of them can be a little confusing at first. To pass this tough certification exam, one term you definitely need to understand is packet switching. The first question, of course, is "What is packet switching in the first place?" Let's define this term in today's Cisco CCNA exam prep tutorial.
Packets transmitted from "point A" to "point B" all have to arrive at the same destination, but with packet switching, they do not all have to take the same path to get there. If you and I are standing 10 feet apart and I want to throw a basketball to you, I've got a couple of options. I could bounce the ball off the floor to you, I could throw it straight at you, or I could throw it high into the air to you. Packet switching is really the same thing - packets will take different paths to get from source to destination, but the end result is that all the packets arrive at the destination. The packets are then reassembled to take the form of the original message. - Cisco Ccna Certification Exam Tutorial: Access List Details You Must Know! By : Chris Bryant, CCIE #12933
To pass the CCNA exam, you have to be able to write and troubleshoot access lists. As you climb the ladder toward the CCNP and CCIE, you'll see more and more uses for ACLs. Therefore, you had better know the basics!
The use of "host" and "any" confuses some newcomers to ACLs, so let's take a look at that first. - Cisco Ccna Certification Exam Tutorial: Configuring And Troubleshooting Vtp By : Chris Bryant, CCIE #12933
Not only is your CCNA exam going to have questions on VLAN trunking protocol, almost any network that has more than one VLAN is going to have VTP running. Whether you're planning on passing the CCNA exam or just brushing up on your networking skills, this VTP tutorial will help you learn the basics of this important protocol.
VTP allows switches to advertise VLAN information between other members of the same VTP domain. VTP allows a consistent view of the switched network across all switches. When a VLAN is created on one switch in a VTP server, all other VTP devices in the domain are notified of that VLAN’s existence. VTP servers will know about every VLAN, even VLANs that have no members on that switch. - Cisco Ccna Certification Exam Tutorial: Configuring Dialer Profiles By : Chris Bryant, CCIE #12933
The most common method of configuring ISDN is with dialer maps, but dial information can also be configured on a logical interface. To pass the CCNA exam, you must know how to configure and troubleshoot both dialer maps and dialer profiles.
Dialer Profiles allow different dialing information to be configured onto logical interfaces. The logical interfaces may have different dialing destinations, different remote router names, etc., but they’ll be using the same physical interface. - Cisco Ccna Certification Exam Tutorial: Distance Vector Command Review By : Chris Bryant, CCIE #12933
Part of studying for CCNA exam success is keeping all these new commands straight in your head! And let's face it, there are a lot of commands you need to know in order to pass the CCNA exam and earn that certification. Here's a review of some very important distance vector and static routing commands you need to know, along with their proper usage and console output.
Bandwidth
IGRP makes a default assumption that any Serial interface running IGRP is connected to a T1 line, which runs at 1544 KBPS. With equal-cost load-balancing enabled by default, this may be an undesirable assumption. - Cisco Ccna Certification Exam Tutorial: Dns And The Ip Name-server Command By : Chris Bryant, CCIE #12933
DNS behaviors of a Cisco router are important topics for both the CCNA exam and real-world production networks, and you probably didn't know there were so many DNS details before you began studying for the exam! In this tutorial, we'll look at the ip name-server command and its proper usage.
When a command is mistyped on a Cisco router, the default behavior of the router is to attempt to resolve it via DNS. First, the router looks for an IP Host table on the local router to perform this resolution – that’s what the “translating” word in the output is referring to. If there’s no IP Host table or the IP Host table doesn’t contain an entry for what you typed, the router will send a broadcast in an attempt to resolve this name through a remote DNS server. To prevent this broadcast, enter the global command no ip domain-lookup. Of course, to use DNS to resolve hostnames, ip domain-lookup would have to be reenabled if it’s been turned off. - Cisco Ccna Certification Exam Tutorial: Frame Relay Dlcis And Mappings By : Chris Bryant, CCIE #12933
Passing the CCNA is tough, and one of the toughest parts is keeping all the acronyms straight! Frame Relay has plenty of those, and today we're going to examine what DLCIs do and how they're mapped on a Cisco router.
Frame Relay VCs use Data-Link Connection Identifiers (DLCI - pronounced "del-see") as their addresses. Unlike other Cisco technologies, VCs have only a single DLCI in their header. They do not have a source and destination. - Cisco Ccna Certification Exam Tutorial: Isdn Details You Must Know By : Chris Bryant, CCIE #12933
CCNA exam success depends partially on knowing the details of ISDN, and there are plenty of them! To help you review for your CCNA exam, here are a few ISDN details that you must know on exam day. (They help in the real world, too – and there are still plenty of ISDN networks out there!
The Cisco-proprietary version of HDLC is the default encapsulation type for serial and ISDN interfaces. - Cisco Ccna Certification Exam Tutorial: Keep Your Most Important Appointment By : Chris Bryant, CCIE #12933
Imagine this. You have an appointment with a client to work on a server or router install. A few minutes before you're scheduled to be there, you decide there's something really good on TV you'd like to watch. Or you decide to go to the gym, or play a game, or do anything else except go see the client.
Even if you weren't going to get fired for not showing up, it's certainly unfair to the client. You've got a professional obligation, and you should be there on time.
Now, what's this got to do with you becoming a CCNA or CCNP? Plenty. Because when it comes to your study time, you're the client. You owe it to yourself to show up. You would never blow off an appointment to meet a client to get some important work done. - Cisco Ccna Certification Exam Tutorial: Ospf Hub-and-spoke By : Chris Bryant, CCIE #12933
CCNA certification demands that you master the basics of OSPF, and for many studying for the CCNA exam, their first exposure to OSPF is a hub-and-spoke configuration. That's a tough way to get started, because a hub-and-spoke configuration built over an NBMA technology such as Frame Relay requires quite a bit of attention to detail. Let's take a quick look at several common OSPF configuration errors and how to avoid them on your CCNA test.
Make sure the hub is the designated router and that there are no backup designated routers. This is done by setting the OSPF interface priority to zero on the spoke routers. This not only ensures that the hub wins the DR election with its default OSPF interface priority of 1, but it prevents the spokes from ever having a chance to become the DR or BDR. - Cisco Ccna Certification Exam Tutorial: Port-based Authentication By : Chris Bryant, CCIE #12933
To pass your CCNA exam and earn this coveted certification, you must understand the details of port-based authentication. This knowledge has a great deal of value in production networks as well, since this authentication scheme is regularly implemented. Let's take a look at this particular CCNA skill.
Consider a situation where you have a server that will be connected to your switch, and you want the port to shut down if a device with a different MAC address that that of the switch attempts to connect to that port. You could also have a situation where you have someone who has a connection to a switch port in his office, and he wants to make sure that only his laptop can use that port. - Cisco Ccna Certification Exam Tutorial: Prefix Notation By : Chris Bryant, CCIE #12933
When you're preparing to pass the CCNA exam and earn this coveted Cisco certification, you've got to be totally prepared for the many kinds of binary and subnetting questions Cisco may throw at you. You also have to be familiar with the different manners in which a subnet mask can be expressed, as in the following:
255.255.255.0 - Cisco Ccna Certification Exam Tutorial: Rip Details You Must Know By : Chris Bryant, CCIE #12933
RIP isn't exactly the most complex routing protocol on the CCNA exam, but that makes it easy to overlook some of the important details you must keep in mind in order to pass the exam! To help you review for the exam, here are just a few of those details!
RIP’s default behavior is to send version 1 updates, but to accept both version 1 and 2 routing updates. - Cisco Ccna Certification Exam Tutorial: The Config Register And Password Recovery By : Chris Bryant, CCIE #12933
Whether you're preparing for the CCNA certification exam or not, you must be prepared for the following question:
"Hey, I reloaded this router and it wants an enable password. Do you know it?" - Cisco Ccna Certification Exam Tutorial: The Osi Model’s Physical Layer By : Chris Bryant, CCIE #12933
To pass your CCNA exam and earn this coveted certification, you've got to master the seven layers of the OSI model and what each layer does. For those of you taking the two-exam path, you can expect quite a few OSI model questions on the Intro exam. In this seven-part series, we'll spend some time taking a look at each of the OSI model layers, starting with the Physical layer.
Often, CCNA candidates ask if the OSI model has any practical uses for network administrators. I used to wonder the same thing, and I can now tell you that the answer is definitely yes! - Cisco Ccna Certification Exam Tutorial: The Ospf Rid By : Chris Bryant, CCIE #12933
OSPF is a major topic on your CCNA exam, as well it should be. OSPF is a widely-used WAN protocol, and you need to learn the fundamentals before moving on to more complicated configurations. One such detail is the OSPF Router ID, or RID.
The RID is the dotted decimal value by which other OSPF routers will identify a given OSPF router. There are some interesting defaults for this value, and a command you should know to hardcode the RID. You had also better know what has to happen for this command to take effect, so let's take a more detailed look at the OSPF RID. - Cisco Ccna Certification Exam Tutorial: Variance And Unequal Cost Load Balancing By : Chris Bryant, CCIE #12933
To pass the CCNA exam, you've got to know how to work with IGRP and EIGRP unequal-cost load balancing. You may not see much IGRP in production networks anymore, but you'll see a lot of EIGRP, and part of fine-tuning your EIGRP network is making sure that all paths are in use while allowing for varying bandwidth rates.
Using the variance command is the easy part - it's getting the metric that's the hard part with IGRP. With EIGRP, you just look in the topology table and that's it. With IGRP, you've got to run a debug to get the right metric. - Cisco Ccna Certification Exam: Five Frame Relay Details You Must Know By : Chris Bryant, CCIE #12933
When you're studying for your CCNA exam on the way to earning this coveted Cisco certification, the details can seem overwhelming! In this article, I'll point out five Frame Relay details that you must keep in mind when you're on your way to the CCNA exam!
Inverse ARP starts working as soon as you open the serial interface. This protocol performs dynamic Frame Relay mapping, but you don't have to enable it - it's already enabled as soon as you enter the command "encapsulation frame-relay". - Cisco Ccna Certification Training Tutorial: Ppp Multilink And Isdn Bri By : Chris Bryant, CCIE #12933
Earning your CCNA certification means you have to notice details about Cisco routers that others might miss, and that's true in the exam room and on the job. In today's tutorial, we'll take a look at multilink PPP - a topic that seems simple enough, but has details that trip up some CCNA certification candidates.
ISDN BRI (Basic Rate Interface) has two B-channels that both carry data, and they each have a capacity of 64 KBPS. Interestingly enough, they don't share the load by default - the first channel has to be at capacity before the second channel starts taking some of the load. It's more efficient to have the channels share the load before then, and we can do just that by configuring PPP multilink. (Note that it's called PPP multilink for a reason. We can't configure it if the BRI interface is running at the default of HDLC.) - Cisco Ccna Certification Training: Etherchannels And Spanning Tree Protocol (stp) By : Chris Bryant, CCIE #12933
Cisco CCNA certification looks great on your resume, and it also teaches you vital real-world networking skills. One exam topic that you'll definitely see in today's networks is the configuration of an Etherchannel on a Cisco router. You need to know how to build and verify one - so let's build one right now!
In this Cisco training tutorial, we'll use two switches that are connected at ports 0/11 and 0/12 via crossover cables. SW1 is the root bridge, SW2 is the non-root bridge. Even though there are two separate physical connections, spanning tree protocol (STP) will only allow the use of one, as verified by the partial output of "show spanning vlan 1" on SW2. - Cisco Ccna Certification Tutorial: Segmenting Your Network By : Chris Bryant, CCIE #12933
When you're getting started on your CCNA studies on your way to earning this certification, you're swamped with network device types that you're familiar with, but not quite sure how to use. Let's look at these networking devices and their main purposes.
Hubs and repeaters operate at Layer One of the OSI model, and they have one main purpose - regenerating the electrical signal that Layer One technologies carry. This regeneration helps to avoid attenuation, the gradual weakening of a signal. Much like a radio signal, the electric signals that travel at Layer One gradually weaken as they travel across the wire. Hubs and repeaters both generate a "clean" copy of the signal. - Cisco Ccna Certification: Broadcasts, Unicasts, And Multicasts By : Chris Bryant, CCIE #12933
When you begin your CCNA studies, you get hit with a lot of different networking terms right away that you might not be familiar with. What makes it a little more confusing is that a lot of these terms sound a lot alike. Here, we're going to discuss the differences between broadcasts, multicasts, and unicasts at both the Data Link (Layer 2) and Network (Layer 3) layers of the OSI model.
A broadcast is simply a unit of information that every other device on the segment will receive. A broadcast is indicated by having every bit of the address set to its highest possible value. Since a hexadecimal bit's highest value is "f", a hexadecimal broadcast is ff-ff-ff-ff-ff-ff (or FF-FF-FF-FF-FF-FF, as the upper case does not affect hex value). The CCNA exam will demand you be very familiar with hex conversions, so if you're not comfortable with these conversions, get comfortable with them before taking the exam! - Cisco Ccna Certification: Cisco Switching Modes Tutorial By : Chris Bryant, CCIE #12933
To pass the CCNA exam and earn that coveted certification, you've got to know Cisco switches inside and out. Among the many important details you've got to know are the three methods that Cisco switches use to forward frames, and the differences between the three.
The first switching method is Store-and-Forward. The name is the recipe, because that's just what the switch does - it stores the entire frame before beginning to forward it. This method allows for the greatest amount of error checking, since the Frame Check Sequence (FCS) can be run before the frame is forwarded. As always, there is a tradeoff, since this error checking process makes this the slowest of the three frame forwarding methods. - Cisco Ccna Certification: Defining And Creating Collision Domains By : Chris Bryant, CCIE #12933
When you're studying to pass the CCNA exam and earn your certification, you're introduced to a great many terms that are either totally new to you or seem familiar, but you're not quite sure what they are. The term "collision domain" falls into the latter category for many CCNA candidates.
What exactly is "colliding" in the first place, and why do we care? It's the data that is being sent out onto an Ethernet segment that we're concerned with here. Ethernet uses Carrier Sense Multiple Access / Collision Detection (CSMA/CD) to avoid collisions in the first place. CSMA/CD is a set of rules dictating when hosts on an Ethernet segment can and cannot transmit data. Basically, a host that wants to transmit data will "listen" to the ethernet segment to see if another host is currently transmitting. If no one else is transmitting, the host will go forward with its own transmission. - Cisco Ccna Certification: Defining Broadcast Domains By : Chris Bryant, CCIE #12933
When you're studying to pass the CCNA exam and earn your certification, you're introduced to a great many terms that are either totally new to you or seem familiar, but you're not quite sure what they are. The term "broadcast domain" falls into the latter category for many CCNA candidates.
A broadcast domain is simply the group of end hosts that will receive a broadcast sent out by a given host. For example, if there are ten host devices connected to a switch and one of them sends a broadcast, the other nine devices will receive the broadcast. All of those devices are in the same broadcast domain. - Cisco Ccna Certification: Error Detection Vs. Error Recovery By : Chris Bryant, CCIE #12933
Passing the CCNA, Intro, and ICND exam is all about knowing and noticing the details. (Which makes perfect sense, since becoming a master networking administrator or engineer is also about noticing the details!) One such detail knows the difference between error detection and error recovery. While the terms are sometimes used interchangeably, they are not the same thing.
Error detection is just that - error detection only. Two common error detection methods are found at the Data Link layer of the OSI model, the FCS (Frame Check Sequence) and CRC (Cyclical Redundancy Check). A mathematical equation is run against the data in the frame, and the result is sent along with the data. The receiver runs the equation again, but this time. If the result is the same, the frame is considered valid; if the result is different, the frame is considered corrupt and is discarded. - Cisco Ccna Certification: Five Key Combinations You Should Know By : Chris Bryant, CCIE #12933
When you start studying for your CCNA and CCNP exams, many books will present you with a huge list of keystroke shortcuts for use on Cisco routers. While the 640-801, 811, and 821 exams may ask you about one or two of these, you really have to get hands-on experience with these commands to master them. Even better, there are some key combinations that Cisco routers mention, but then don't tell you what they are! Let's take a look at a few of the more helpful key combinations, and conclude with the "secret" way to stop a ping or traceroute.
The up arrow on your keyboard is great for repeating the last command you typed. Let's say you mis-enter an access-list. Instead of typing it from the beginning, just hit your up arrow to repeat it, then fix the problem. - Cisco Ccna Certification: How And Why Switches Trunk By : Chris Bryant, CCIE #12933
Your CCNA studies are going to include quite a bit of information about switches, and for good reason. if you don't understand basic switching theory, you can't configure and troubleshoot Cisco switches, either on the CCNA exam or in the real world. That goes double for trunking!
Trunking is simply enabling two or more switches to communicate and send frames to each other for transmission to remote hosts. There are two major trunking protocols that we need to know the details of for exam success and real-world success, but before we get to the protocols, let's discuss the cables we need. - Cisco Ccna Certification: Static Routing Tutorial By : Chris Bryant, CCIE #12933
In studying for your CCNA exam and preparing to earn this valuable certification, you may be tempted to spend little time studying static routing and head right for the more exciting dynamic routing protocols like RIP, EIGRP, and OSPF. This is an understandable mistake, but still a mistake. Static routing is not complicated, but it's an important topic on the CCNA exam and a valuable skill for real-world networking.
To create static routes on a Cisco router, you use the ip route command followed by the destination network, network mask, and either the next-hop IP address or the local exit interface. It's vital to keep that last part in mind - you're either configuring the IP address of the downstream router, or the interface on the local router that will serve as the exit interface. - Cisco Ccna Certification: The (many) Different Kinds Of Switching By : Chris Bryant, CCIE #12933
When you're studying for your CCNA exam, whether you're taking the Intro-ICND path or the single-exam path, you're quickly introduced to the fact that switching occurs at Layer 2 of the OSI model. No problem there, but then other terms involving switching are thrown in, and some of them can be more than a little confusing. What is "cell switching"? What is "circuit switching"? Most confusing of all, how can you have "packet switching"? Packets are found at Layer 3, but switching occurs at Layer 2. How can packets be switched?
Relax! As you'll see in this article, the terms aren't that hard to keep straight. Packet switching, for example, describes a protocol that divides a message into packets before they're sent. The packets are then sent individually, and may take different paths to the same destination. Once the packets arrive at the final destination, they are reassembled.
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