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Cisco Ccna Ccnp Certification Ospf E2 Vs E1 Routes

(category: Computer-Certification, Word count: 587)
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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 [110/20] via, 00:33:21, Ethernet0 is subnetted, 1 subnets

O E2 [110/20] via, 00:33:21, Ethernet0 is variably subnetted, 2 subnets, 2 masks

O E2 [110/20] via, 00:33:32,


O E2 [110/20] via, 00:33:21, Ethernet0 is subnetted, 1 subnets

O E2 [110/20] via, 00:33:32, Ethernet0

E2 is the default route type for routes learned via redistribution. The key with E2 routes is that the cost of these routes reflects only the cost of the path from the ASBR to the final destination; the cost of the path from R4 to R1 is not reflected in this cost. (Remember that OSPF's metric for a path is referred to as "cost".)

In this example, we want the cost of the routes to reflect the entire path, not just the path between the ASBR and the destination network. To do so, the routes must be redistributed into OSPF as E1 routes on the ASBR, as shown here.

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#router ospf 1

R1(config-router)#redistribute rip subnets metric-type 1

Now on R4, the routes appear as E1 routes and have a larger metric, since the entire path cost is now reflected in the routing table.

O E1 [110/94] via, 00:33:21, Ethernet0 is subnetted, 1 subnets

O E1 [110/100] via, 00:33:21, Ethernet0 is variably subnetted, 2 subnets, 2 masks

O E1 [110/94] via, 00:33:32, Ethernet0

O E1 [110/94] via, 00:33:21, Ethernet0 is subnetted, 1 subnets

O E1 [110/94] via, 00:33:32, Ethernet0

Knowing the difference between E1 and E2 routes is vital for CCNP exam success, as well as fully understanding a production router's routing table. Good luck in your studies!

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How To Succeed At A Computer Training School

(category: Computer-Certification, Word count: 413)
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One of the best decisions you can ever make is to attend a computer training school. As I've written in several other articles, you have to ask the right questions before writing a check or taking out a student loan, but when you find the right school you are indeed on your way to a successful career.

There's a big difference between attending a tech school and excelling at the classes, though. Whether you just "float through" the school or really work hard is totally up to you. From my personal experience at such a school, I'd like to offer you one simple tip that will quadruple your chances of success at the school and in the job market.

Get there early and stay late.

When I attended a tech school years ago, I admit I was surprised that most of my classmates had what I call the "junior high school" mentality - they would get there late and leave as soon as class is over. Guess what? You're no longer in junior high. You're attending this school to create a career for yourself. Get to class early, get some extra study and work in while you're waiting for class to start, and then stay after class!

The most important part of your computer school studies is getting hands-on experience with the technologies that you're learning. If you're taking a Cisco class, you need to work with a router or switch as often as you can. If you're learning a software program, you need to work with that program in the school's labs as much as possible. Reading books alone will not teach you everything you need to know. The best time to get extra work in is after class. You may not be able to work in the computer labs at night if the school offers night classes, but odds are there are very few people in there during the afternoon. You need to be one of those people.

Doing only what is required of you is not the path to excellence. You need to go beyond the requirements of the school and invest the extra time and effort into your career. I speak from experience - there is no field in the world that rewards individual effort more than the IT field. Develop the habit of going "above and beyond" today, and this will pay huge dividends for you in the future.

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Cisco Ccna Ccnp Certification Exam Review Protocol Basics

(category: Computer-Certification, Word count: 316)
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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 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.

RIPv2: Multicasts updates every 30 seconds to the address RIPv2 is a classless protocol, allowing the use of subnet masks. Update contains entire RIP routing table. Uses Bellman-Ford algorithm. Allows equal-cost load-balancing by default. Max hop count is 15. Supports clear-text and MD5 authentication of routing updates. Updates carry 25 routes maximum.

IGRP: Broadcasts updates every 90 seconds to the address IGRP is a Cisco-proprietary protocol, and is also a classful protocol and does not recognize subnet masking. Update contains entire routing table. Uses Bellman-Ford algorithm. Equal-cost load-balancing on by default; unequal-cost load-sharing can be used with the variance command. Max hop count is 100.

EIGRP: Multicasts full routing table only when an adjacency is first formed. Multicasts updates only when there is a change in the network topology, and then only advertises the change. Multicasts to and allows the use of subnet masks. Uses DUAL routing algorithm. Unequal-cost load-sharing available with the variance command.

By mastering the basics of these protocols, you're laying the foundation for success in the exam room and when working on production networks. Pay attention to the details and the payoff is "CCNA" and "CCNP" behind your name!

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Passing Cisco S Ccna And Ccnp Exams Traceroute

(category: Computer-Certification, Word count: 489)
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In preparation for your CCNA and CCNP exam success, you've got to learn to troubleshoot Cisco routers. And while ping is a great basic IP connectivity tool, it doesn't give you all the information you need to diagnose network connectivity issues.

Let's say you have six routers between CityA and CityB. You send a ping from A to B, and get this return:


Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:


Success rate is 0 percent (0/5)

The five periods indicate that there is no IP connectivity to CityB. Problem is, that's about all ping tells you. You can have 5 or 50 routers between the two points, so how can you tell which downstream router has the problem?

That's where traceroute comes in. Traceroute sends three datagrams with a Time To Live (TTL) of 1. Those datagrams will timeout once they hit the first router in the path, and that router will respond with an ICMP Time Exceeded message.

In response, the sending router sends three more datagrams, but these have a TTL of 2. This means that the next router in line will send back ICMP Time Exceeded messages. This process continues until the final destination (CItyB) is reached the output of the command shows us the path the data took:


Type escape sequence to abort.

Tracing the route to

1 4 msec 4 msec 4 msec

2 20 msec 16 msec 16 msec

3 16 msec * 16 msec

How does this help troubleshoot a problem? Let's say that the second router in this path,, doesn't know how to get to The output would look like this:


Type escape sequence to abort.

Tracing the route to

1 4 msec 4 msec 4 msec

2 20 msec 16 msec 16 msec

3 * * *

This indicates that the router at doesn't know how to get to the final destination. Now you have a better idea of which router has an issue!

Now here's the bad part: you're going to get 30 lines of three asterisks, and until you abort this traceroute, you're going to just watch those asterisks go across the screen. There's an abort sequence that the router mentions in the first line of the console output, but the router doesn't tell you what it is! So I will - this top-secret sequence is TWICE, one right after the other.

That keystroke takes a little getting used to, but a CCNA or CCNP can do it! Add this command to your Cisco skill set, and it will serve you well both on the CCNA and CCNP exams and your real-world networks. And you'll impress your friends by knowing how to stop a traceroute!

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Boost Your Career And Benefit From A Microsoft Certification Or Two Or Three

(category: Computer-Certification, Word count: 521)
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You went to college and thought you were prepared for the job market. If you are going for entry-level work, yeah, you are prepared. However, to really get ahead, you need Microsoft certification, whether it is an MCP, MCSA, MCSE or any other string of letters. Quite a few people will go for multiple certifications to broaden their experience and scope of possible job opportunities.

Some of the Microsoft certifications require you have to have at least one year of practical experience in order to pursue a certification, namely an MCSE or Microsoft Certified Systems Engineer. It is important to have that experience that these certain certifications require because the training, like the MCSE training and the MCSE exams that follow, are very intense. In fact, some people will not only partake of the standard MCSE training, but also MCSE boot camps for more in-depth studies into their certification.

One standard benefit to having a Microsoft certification is that it is a great basic means of analyzing the aptitude of an employee. If you are a manager or owner in a business, you want some way to evaluate that employee's skills. And if you are the employee, you know that your boss recognizes your abilities.

If you are on the hunt for a new job, then potential hiring managers and employers have a basis in which to assess your qualifications. Without that Microsoft certification on your resume, these employers would have no idea about your skills and most likely would consider someone else, someone with a certification, for the position you were aiming for.

If you do not have much hands-on experience in your field, but you do have the Microsoft certification to prove that you know the material, you would also have a leg up on anyone else applying for the same position that may have more hands-on experience, but no certification. For some reason, that certification, those little string of letters like MCP or MCSE, hold a lot of power.

Yet another benefit to holding a Microsoft certification or two is the money aspect of it all. Sure, you shelled out some major bucks to fund your education in those MCP courses or that MCSE training, but consider it an investment in yourself. With certification, you can bargain a higher salary and even reimbursement for your training!

Many professionals in the IT field or in a company in which you work in an IT department could benefit from Microsoft certification. Do you work as an Administrator for a network, mail or web server? Are you involved in the security of networks and the internet? Any of those positions and much more benefit with additional training and certification. Just think money! It is the biggest motivator. The more you know and can bring to a position, the more money you stand to make.

So think about going for your MCSE or MCP certification or any number of others available. More training; more knowledge; more money ... sounds like a no-brainer! Go nuts and get certified today!

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Cisco Ccna Certification Exam Tutorial The Osi Model S Physical Layer

(category: Computer-Certification, Word count: 392)
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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!

The OSI model isn't something you want to memorize and then forget about, as using the OSI model gives you a structured approach for troubleshooting. Whenever a network device isn't working properly, I always say to "start at the physical layer". The Physical layer is Layer One of the OSI model, and this is where troubleshooting should always start. Is the device on? Is it properly connected? If everything is fine at Layer One, you just move up to Layer Two, and continue in this structured fashion until the problem is identified.

The Physical layer is the layer at which bits are transmitted over the physical media. There is no routing or switching going on at this layer. The data has been broken down into more manageable pieces until the data takes the form of ones and zeroes at the Physical layer.

Even though there's no routing or switching at the Physical layer, CCNA candidates should be familiar with a couple of network devices that work at Layer One. A repeater is a device that regenerates an electrical signal, allowing the signal to travel longer distances without fading. (The process of an electrical signal gradually fading in strength over distance is "attenuation".) A hub is basically a multiport repeater, and both of these devices are considered Physical layer devices. Ethernet and Token Ring both operate at the Physical layer as well.

Learning the OSI model's Physical layer isn't just important in your CCNA exam studies, it's the first step in any network troubleshooting. After all, your network's end users are going to have a tough time sending print jobs to a printer that's turned off!

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Cisco Ccna Exam Tutorial Igrp And Equal Cost Load Balancing

(category: Computer-Certification, Word count: 574)
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To pass the CCNA exam, you've got to know the role of the bandwidth command with IGRP and EIGRP and when to use it. In this tutorial, we'll configure IGRP over a frame relay hub-and-spoke network using the following networks:

R1 (the hub), R2, and R3 are running IGRP over the /24 network. This is a T1 line.

R1 and R3 are also connected on a different subnet, /24. The bandwidth of this connection is 512 KBPS.

R2 and R3 are also connected by an Ethernet segment, /16.

We'll configure IGRP on R1, R2, and R3 with the router igrp 1 command. IGRP will run on all interfaces in the and network.

R1#conf t

R1(config)#router igrp 1


The "1" in the router igrp command refers to the Autonomous System (AS). IGRP is a classful routing protocol, so wildcard masks are not used in the network statements.

R2#conf t

R2(config-if)#router igrp 1



R3#conf t

R3(config-if)#router igrp 1



Run show ip route on R1. R1 will see three equal-cost paths to the Ethernet network. IGRP supports load-sharing over up to four equal-cost paths by default, so all three paths appear in the routing table. R1 will also see a route to the loopback address on R2 and two routes to the loopback address on R3. (You can also run show ip route igrp in order to see only the IGRP routes.)

R1#show ip route igrp

I [100/8576] via, 00:00:02, Serial0

[100/8576] via, 00:00:02, Serial1

[100/8576] via, 00:00:01, Serial0

Remember that the numbers in the brackets following the network number in the routes are the Administrative Distance and the IGRP metric, in that order.

Note that classful masks are in use. IGRP does not support variable-length subnet masks (VLSM).

There are two serial connections between R1 and R3. IGRP is assuming that both lines are T1 lines, running at 1544 KBPS. The network is participating in equal-cost load sharing because of IGRP's bandwidth assumption - that all serial interfaces are connected to T1 lines.

To give IGRP a more accurate picture of the network's bandwidth, configure bandwidth 512 on R1 and R3's Serial1 interface (the interfaces on the network).

R1#conf t

R1(config)#interface serial1

R1(config-if)#bandwidth 512

R3#conf t

R3(config)#interface serial 1

R3(config-if)#bandwidth 512

IGRP's assumption that all serial lines run at 1544 KBPS is overridden by the bandwidth 512 command. IGRP now believes this line runs at 512 KBPS.

To see the effect of this command, clear your routing table on R1.

R1#clear ip route *

R1#show ip route igrp

I [100/8576] via, 00:00:24, Serial0/0

[100/8576] via, 00:00:17, Serial0/0

The routing table is cleared with clear ip route *. To see only the routes received in IGRP updates instead of the entire table, run show ip route igrp.

One of the paths to is now gone - the route that went through the network. Now that IGRP sees that link as slower than the others, equal-cost load balancing will not occur over the network.

It's important to understand that the bandwidth command does not actually change the bandwidth of the connection; it changes IGRP's assumption of what the bandwidth is.

In the next part of this IGRP load-balancing tutorial, we'll take a look at how to configure unequal-cost load balancing.

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Computer Certification Become A Utility Player

(category: Computer-Certification, Word count: 391)
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In baseball, a "utility player" is one who plays more than one position. These players are usually backups, but they have a job in the major leagues because of their value to the team; since they can play more than one position, they have that much more value to their employer.

Too often in IT, workers become either LAN or WAN engineers, knowing little if anything about the other side. Many LAN administrators I worked with knew little about routing and switching, while many WAN engineers I knew not only didn't know much about the LAN side of their network, but they didn't want to know anything about the servers!

In today's IT world, it's a bad idea to specialize in only one thing and not know how to do anything else. Not only does it limit your future career prospects, but it limits your current prospects as well. Employers don't want to hire someone and have them get up to speed on the job - they want someone who can walk right in and do the job. The more you know, the better your chance of getting a better job - or quickly being able to get another job if you were laid off tomorrow.

A term often heard on Wall Street is "diversification", meaning that investors should not invest heavily or totally in only one stock; if that stock plummets, they're in big trouble. Your career is the most important stock you will ever own, and you're 100% in charge of it. Diversify. If you're working primarily with servers, learn some routing and switching. If you know the routing protocols your company uses on its WAN, learn something about that protocol. (If you don't know the protocol, ask!)

While you're adding these skills, get certified while you're at it! Adding a CCNA, MCSE, or other computer certification looks great on your resume while signaling to employers that you're constantly adding to your skills.

Adding more skills and knowledge to your IT skill set is always a good idea. Don't limit yourself to the technologies you work with every day. Make an investment in yourself and become a well-rounded network engineer. This will help you keep the job you have - and open doors in the future that might otherwise have remained closed.

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Cisco Ccnp Bcmsn Exam Tutorial The Core Layer Of Cisco S Three Layer Model

(category: Computer-Certification, Word count: 441)
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In this section, you're going to be reintroduced to a networking model you first saw in your CCNA studies. No, it's not the OSI model or the TCP/IP model - it's the Cisco Three-Layer Hierarchical Model. Let's face it, just about all you had to do for the CCNA was memorize the three layers and the order they were found in that model, but the stakes are raised here in your CCNP studies. You need to know what each layer does, and what each layer should not be doing. This is vital information for your real-world network career as well, so let's get started with a review of the Cisco three-layer model, and then we'll take a look at each layer's tasks. Most of the considerations at each layer are common sense, but we'll go over them anyway!

Today we'll take a look at the core layer of the Cisco model.

The term core switches refers to any switches found here. Switches at the core layer allow switches at the distribution layer to communicate, and this is more than a full-time job. It's vital to keep any extra workload off the core switches, and allow them to do what they need to do - switch! The core layer is the backbone of your entire network, so we're interested in high-speed data transfer and very low latency - that's it!

Core layer switches are usually the most powerful in your network, capable of higher throughput than any other switches in the network. Remember, everything we do on a Cisco router or switch has a cost in CPU or memory, so we're going to leave most frame manipulation and filtering to other layers. The exception is Cisco QoS, or Quality of Service. QoS is generally performed at the core layer. We'll go into much more detail regarding QoS in another tutorial, but for now, know that QoS is basically high-speed queuing where special consideration can be given to certain data in certain queues. (You'll soon find that this is a very basic definition!)

We always want redundancy, but you want a lot of redundancy in your core layer. This is the nerve center of your entire network, so fault tolerance needs to be as high as you can possibly get it. Root bridges should also be located in the core layer.

The importance of keeping unnecessary workload off your core switches cannot be overstated. In the next part of this BCMSN tutorial, we'll take a look at how the other layers of the Cisco three-part model do just that.

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