Archive for the 'Computer Certification' Category

by Chris Bryant, CCIE #12933
Your CCNA and CCENT exam success depends on knowing how to configure and troubleshoot HDLC and PPP on Cisco routers, as well as knowing the differences and similarities between the two. Today we’ll take a look at HDLC and some basic router configurations, and in future CCNA and CCENT certification exam tutorials, we’ll examine PPP in detail.

With a point-to-point WAN link such as the following, we’ve got two options for encapsulation - HDLC and PPP. (HDLC, PPP, and Frame Relay do not run on LANs - you wouldn’t configure them on Ethernet interfaces.)

We’re not going to discuss HDLC for long, since there’s not much to say about it - but what there is to say is very important! The version of HDLC used by Cisco routers is the default encapsulation type on Serial interfaces, verifiable with the show interface serial command. (Only the portion of this command’s output dealing with the PTP WAN link will be shown in this section.)

R1#show interface serial 1
Serial1 is up, line protocol is up
Hardware is HD64570
Internet address is 172.12.13.1/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set

R3#show int serial1
Serial1 is up, line protocol is up
Hardware is HD64570
Internet address is 172.12.13.3/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set

At this point, each partner in the PTP link can ping the other.

R1#ping 172.12.13.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.12.13.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms

R3#ping 172.12.13.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.12.13.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms

This particular version of the High Data-Link Control encapsulation is Cisco-proprietary, a fancy way of saying “only Cisco routers understand this encapsulation type”. If a router at the end of a PTP link is running HDLC encapsulation, the remote partner in the link must do so as well.

If one of the routers is running another encapsulation type, the physical interfaces will still be up, but the line protocol will go down and IP connectivity will be lost. To illustrate, I’ll change the encapsulation type on R3’s Serial1 interface to the Point-To-Point Protocol (PPP).

R3(config-if)#exit
R3(config)#int serial 1
R3(config-if)#encapsulation ppp

A few seconds later, the line protocol goes down on R3.

2d04h: %SYS-5-CONFIG_I: Configured from console by console
2d04h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down

show interface serial 1 on both routers verifies that the physical interface is up, but the line protocol is down. IP connectivity is lost.

R3#show interface serial 1
Serial1 is up, line protocol is down

R3#ping 172.12.13.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.12.13.1, timeout is 2 seconds:
…..
Success rate is 0 percent (0/5)

R1#show interface serial 1
Serial1 is up, line protocol is down

R1#ping 172.12.13.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.12.13.3, timeout is 2 seconds:
…..
Success rate is 0 percent (0/5)

The encapsulation mismatch has brought the line protocol down, and to bring it back up, we simply need to make the encapsulation types match again. We’ll do just that in the next installment of my exclusive Cisco CCENT / CCNA certification exam tutorial series!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free Cisco CCNA 640-802 certification exam study guides, CCNA 640-802 tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages. You can also visit his blog, which is updated several times daily with new Cisco certification articles, free tutorials, and daily CCNA / CCNP exam questions! For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Take the CCNA Mastermind Webinar Boot Camp with The Bryant Advantage!

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by vishal verma
The dramatic rise in demand for technology has seen a rise in the demand for professionals within this field. Anyone wishing to enter a career in computer and information technology will find a variety of suitable degrees and courses that can help with their career. Those already working in a computer and IT related field can also gain from these courses, as they can aid career advancement.

Online technology degrees are popular because

Technology specializations and career opportunities are continuously expanding

Online learning with rich, interactive media is the ideal “classroom” for all aspects of IT.

Technology platforms, standards and best-practices change quickly, and online course materials are continuously updated

Courses available in technology and information technology

Computer information systems degree: A CIS degree prepares you for entry positions within the IT field. Those already working in a junior position can also benefit from a Computer Information Systems degree, as this can lead to an increased chance of promotion.

Computer networking degree: A computer networking degree helps you to learn and develop the skills and knowledge required for work, as well as enabling those already working with computers in advancing their careers. Qualified and capable computer networking professionals are always in demand.

Computer programming degree: For those already working a computer programming degree is an effective tool and valuable asset in career advancement.    It will help you secure a more competitive salary. This is a specialist role that requires special knowledge and skills, and the computer programming degree program is the perfect way to learn and develop these skills.

Computer science degree: If you are want to get an entry level position in computer technology and science, this degree will prove invaluable. Computer related positions are very well paid and trained, able professionals are always in demand. If you already work in the area of computer technology, a computer science degree is the ideal way to pursue career advancement.

Engineering degree: An engineering job in the computer industry can be a wide-ranging and interesting one, and you could be working for all sorts of companies, from banks and pharmaceutical companies to governments and law enforcement agencies. All businesses need access to competent engineers should the need arise.

Information technology degree: An IT degree is valuable for those wanting to begin in the IT field as well as for those already working in IT. This degree will prove to possible employers that you have the specialist skills and knowledge required to work in this particular field. you may cover a variety of IT areas, such as networking, database administration, and programming etc.

Management information technology Master degree: With a this degree under your belt, you could find yourself working for high profile companies as well as smaller ones. Your management information technology Master degree will be looked upon positively by potential employers, and will show that you have mastered the skills and knowledge necessary to succeed in a higher level IT role.

MCSE training/degree: The MSCE training/degree qualification is highly valued by employers and can lead to a very satisfying, well paid position. When you undertake MSCE training/degree courses you will be trained in the latest methods and technologies, and you will develop the skills and knowledge required to work with proficiency and confidence in the area of Microsoft solutions and infrastructures.

Network security certification: Network security certification is a necessity for those wanting to work in the area of network security, enabling them to provide an important service that protects computer users from the risks of data theft and security breaches. With network security certification, you can develop the skills and knowledge required to build and implement defensive security strategies.

Web development training: On completion of your web development training, you will have specialist skills and knowledge in the use of a variety of popular applications, ranging from JavaScript and Flash to Dreamweaver and FrontPage. Your web development training will provide you with an important base that will enable you to enjoy career and advance in it.

Vishal Verma is an Internet infopreneur who has website on eLearning solutions India , Different types of LMS are discussed including learning management system and offers e-learning services India.

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by Chris Bryant, CCIE #12933
An important part of your Cisco CCENT and CCNA certification studies is learning the differences between RAM, ROM, NVRAM, and Flash memory. You better know the differences when it comes to working in real-life networks as well, because vital Cisco files are found in these memory types - and since some of these files are lost on a router reload and some are not, we better know which is which!

The memory types and functions discussed in this section are the same for routers and switches, but to keep from saying “routers and switches” 500 times, I’ll just say “routers”.

Configuring the routers is a lot of fun, but we’ve got to know what’s going on inside the router, too! Cisco routers have four different kinds of memory, and while some of the names are similar, their purpose is totally different.

The contents of some of these memory types is kept when the router is reloaded, and others are lost on a reload. We better know which is which!

It’s a fair bet that these topics will come up on your CCENT and CCNA exams, and this is also information you’ve got to know to be a real network admin. Let’s examine these four memory types closely and see what each one does!

ROM: Read-Only Memory. ROM stores the router’s bootstrap startup program, operating system software, and power-on diagnostic test programs (POST).

Flash Memory: Generally referred to simply as “flash”, the IOS images are held here. Flash is erasable and reprogrammable ROM. Flash memory content is retained by the router on reload.

RAM: Random-Access Memory. Stores operational information such as routing tables and the running configuration file. RAM contents are lost when the router is powered down or reloaded. By default, routers look here first for an Internetwork Operating System (IOS) file during boot.

NVRAM: Non-volatile RAM. NVRAM holds the router’s startup configuration file. NVRAM contents are not lost when the router is powered down or reloaded.

Some important comparisons:

RAM contents are lost on reload, where NVRAM and Flash contents are not.
NVRAM holds the startup configuration file, where RAM holds the running configuration file.
Let’s take a look at the boot process of a Cisco router, and then talk about the dreaded Setup Mode!

The Router Boot Process

When a Cisco router powers up, it first runs a series of POSTs (Power-On Self Test). A POST is a series of diagnostic tests designed to verify the basic operation of the network interfaces, memory, and the CPU.

Depending on the model or router of switch you’re using, you can actually see some of these tests being passed. Here, I’ve reloaded a Cisco 2950 switch, and you can see some of the POSTs being run and passed at the very beginning of the bootup process.

Initializing flashfs…

flashfs[1]: 79 files, 3 directories

flashfs[1]: 0 orphaned files, 0 orphaned directori

flashfs[1]: Total bytes: 7741440

flashfs[1]: Bytes used: 5980672

flashfs[1]: Bytes available: 1760768

flashfs[1]: flashfs fsck took 7 seconds.

flashfs[1]: Initialization complete.

Done initializing flashfs.

POST: System Board Test : Passed

POST: Ethernet Controller Test : Passed

ASIC Initialization Passed

POST: FRONT-END LOOPBACK TEST : Passed

POSTs are particularly effective at detecting major problems early in the boot process, such as a broken fan. If the POST detects such a problem (usually called an “environmental factor”) that would cause the router or switch to overheat after booting, the POST will fail, give you a clear message as to why the POST failed, and will then stop the boot process.

But let’s speak positively here!

After the router passes the POST, it looks for a source from which to load a valid Internetwork Operating System (IOS). The router has three sources from which it can load an IOS image, and it’s a good idea to know these sources and the order in which the router will look in each for the IOS image:

1. Flash memory (the default).

2. A TFTP server. (Trivial File Transfer Protocol)

3. Read-Only Memory (ROM)

To change that order, a change must be made to the configuration register, and we’ll talk about that later in the course. It’s similar to the Microsoft Registry in that you should never change this value unless you are sure of the result.

Once the IOS is found, the router looks for a valid startup configuration file. By default, the router will look for the startup configuration file in Non-volatile RAM (NVRAM).

If no valid startup configuration file is found, the router enters setup mode, where the router runs the system configuration dialogue, a series of questions involving basic router setup. We’ll take a look at Setup Mode in the next installment of my exclusive 640-802 CCNA and CCENT certification exam tutorial series!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free Cisco CCNA 640-802 CBTs and study guides , CCNA 640-802 tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages. You can also visit his blog, which is updated several times daily with new Cisco certification articles, free tutorials, and daily CCNA / CCNP exam questions! For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Pass your Cisco CCENT and 640-802 CCNA exams with The Bryant Advantage!

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by Chris Bryant, CCIE #12933
Basic network troubleshooting is a vital part of your Cisco CCENT and CCNA exam studies, and it’s obviously an important part of what we do as network admins on a day-to-day basis. In today’s free Cisco certification training tutorial, we’ll take a look at the output of show interface serial under different circumstances, concentrating on the physical and logical state of the interface.

To be an effective troubleshooter, you have to know how things look when all is well, not just when something is broken! When an interface is functioning correctly, this is what we see at the top of the show interface output. I’ll use Serial0 for all examples in this section.

Router1#show int serial0

Serial0 is up, line protocol is up

Of course, if the interface looked like that all the time, we wouldn’t be troubleshooting, would we? Let’s take a look at common show interface outputs that do indicate a problem, along with the solutions for these issues.

Router1#show int serial0

Serial0 is administratively down, line protocol is down
This one’s easy! administratively down means the interface is indeed shut down. Open the interface with no shutdown.

Router1(config)#int serial0

Router1(config-if)#no shutdown

Always give the line protocol a minute or so to come up after opening a serial interface.

Router1#show interface serial0

Serial0 is up, line protocol is up
Success! Let’s look at another potential readout:

Router1#show interface serial 0

Serial0 is down, line protocol is down
The physical interface is again down, but not administratively down. This indicates a physical problem, either with the interface or the cable attached to it. Or not attached, as the case may be.

From years of experience, I can tell you that a cable that looks fully attached to a router may not be. If you see this particular output, check the cable and make sure it’s connected. Even if it looks like it’s not, give it a little push in anyway. (Don’t push it through the other side of the router, that defeats the purpose of troubleshooting!)

A lot of router cabinets are crowded, and if a cable is nudged accidentally by an admin’s elbow, that can be enough to bring the connection down. (Not that I’ve ever done that, you understand!)

After making sure the cable is plugged in….

Router1#

20:14:47: %LINK-3-UPDOWN: Interface Serial0, changed state to up

20:14:48: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up

… the link comes back up. Of course, we’ll verify that before moving to the next example!

Router1#show int serial 0

Serial0 is up, line protocol is up

There’s one more physical / line protocol combination we have to be ready to troubleshoot, and it’s a common one:

Router1#show int serial 0

Serial0 is up, line protocol is down

Here, the interface is physically fine, but there is a logical problem. This can be due to an encapsulation mismatch, such as when one partner in a point-to-point connection is configured for HDLC and the other for PPP.

Configuring both ends of the point-to-point link for the same encapsulation will bring the line protocol back up.

Whether the DCE is a CSU/DSU or another Cisco router in a home lab, the DCE must supply a clockrate to the DTE. If that clockrate is not present, the line protocol will come down.

The show interface serial command is vital for WAN troubleshooting, and knowing how to handle the different results we’ve seen here are a major step forward in you passing your CCENT and CCNA exams! We’ll look at some LAN troubleshooting techniques in the next installment of my exclusive Cisco CCENT and CCNA tutorial series!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free Cisco CCNP, BSCI, and BCMSN training and CCNA 640-802 tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages. You can also visit his blog, which is updated several times daily with new Cisco certification articles, free tutorials, and daily CCNA / CCNP exam questions! For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Pass your Cisco CCENT and CCNA 640-802 exam with The Bryant Advantage!

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by Alan Calder
Managers who claim that their organizations comply with ISO/IEC 27001:2005 but that they see no need to go through the bureaucracy of getting the ‘badge on the wall’ are only deceiving themselves. The reality, I suspect, is that the vast majority of organizations that won’t submit their Information Security Management Systems (ISMS) to an external audit against ISO 27001 fear that, when it comes to the push, their systems would fail the test.

Survey after survey tells a depressingly familiar information insecurity story. Most recently, the 10th annual CSI/FBI survey revealed that, amongst the security-conscious, information security control-focused members of the CSI, computer crime continued to have a significant financial impact. The average incident last year cost $204,000, and the top two security breaches were through virus attacks and unauthorized access — both of which are comprehensively controlled through the controls and management systems mandated by ISO 27001.

ISO27001 Effectively Manages Data Security

This evidence, combined with the findings of a recent survey carried out amongst UK-based organizations that ISO27001, suggests — somewhat contradictorily — that securing information is rarely the primary driver for achieving certification. The top reason was commercial advantage, summed up by one respondent who said that a certificate ‘gives customers confidence that our data security is well managed and certified by an independent source.’
And it’s that certification ‘by an independent source’ which is the real benefit of pursuing ISO 27001 in the first place. US regulators implicitly recognized the importance of external validation for information security effectiveness when they observed that: ‘the best way to strengthen US information security is to treat it as a corporate governance issue that requires the attention of boards and CEOs.

Achieve High Security Standards through ISO 27001

There are sectors in which the ‘badge on the wall’ debate is already history, and in which certification is now becoming a basic business requirement. UK cheque printers, for instance, are required to comply with a sectoral version of ISO27001 and suppliers to the NHS are expected to be on track for certification (there is now a health sector version of ISO17799) — even if the NHS itself still has some way to go. Business Process Outsourcing companies are finding it much simpler to provide a copy of their ISO 27001 certificate in their tender documentation than to answer detailed information security questionnaires.
Some of this might be expected: BS7799 was, after all, a British Standard, and the UK government’s Cabinet Office has, for several years now, driven take-up across the UK public sector. And as more and more local authorities and public-sector organizations become certified, so the pressure for their private-sector suppliers to achieve the standard will increase — and today’s early adopters are clearly stealing a march on their competitors.

Achieve Your Certificate in ISO 27001

Internationalised as ISO 27001, information security certification can also be a short cut to best-practice compliance with a wide range of data compliance and regulatory requirements, ranging from Data Protection Acts across the EU, privacy and breach legislation across the OECD, and specific legislation such as GLBA, HIPAA and Sarbanes Oxley. Determined outsourced suppliers are increasingly insisting that their certificate be taken into account when preparing for and costing their annual SAS 70 audit, with consequently substantial reductions in both the cost of, and disruption caused by, the audit.

Are organizations beginning to recognize that, in fact, it is the badge on the wall that counts? Yes, as evidenced by the increasing number of badges. It took about seven years (to December 1994) for the first 1,000 certificates to be achieved, but less than two and half years later there are more than 3,500 successes. And certification has a ripple effect: every organization that achieves ISO 27001 will expect its key suppliers to meet the standard. And this means that anyone who thinks the badge doesn’t count will have nowhere to hide when the CEO comes asking why your competitors have stolen your lunch.

1 BS7799 Survey 2005, Information Security Ltd
2 ‘Information Security Governance: a Call to Action’, US National Cyber Security Summit Task Force, April 2004

About the Author:Alan Calder is an international authority on IT Governance and information security management. He led the world’s first successful implementation of BS 7799, the information security management standard upon which ISO 27001 is based, and wrote the definitive compliance guide for this standard, ‘IT Governance: A Manager’s Guide to Data Security and BS7799/ISO17799’.

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by Chris Bryant, CCIE #12933
To pass the Cisco CCENT and CCNA certification exams, you have to know what cable type is appropriate for a given situation. It’s also a good idea to know this for working in real-world production networks as well! After all, if we have the wrong cable, we don’t have a network!

This is particularly true of the following scenario, where we have:

A laptop connected to a switch (Cable 3)

Two switches connected to each other (Cable 2)

A PC connected to a switch (Cable 1)

This is a very basic and common topology, but we’ve got three different cable types in there! Working from top to bottom, let’s take a look at the different cables we’ll need to make this work.

For Cable 1, we need a straightthrough cable. A straightthrough cable is used to connect a PC to a switch or hub. In a straightthrough cable, the wire connected to Pin 1 on one side is connected to Pin 1 on the other, the wire connected to Pin 2 on one side is connected to Pin 2 on the other, and so forth.

It’s very common to connect two switches to allow them to send data over that connection, and the connection between two switches is called a trunk. You’ll learn all about the particulars of trunking in your CCNA studies, but the first thing we have to do is make sure we have the correct cable!

To allow two switches to communicate with each other, a special cable type is needed. Regular straight-through cables will not allow two switches to form a trunk.

What we need is a crossover cable. The wire connected to Pin 1 on one side will no longer be connected to Pin 1 on the other, as it was in a straight-through cable.Four wires will “cross over” in a crossover cable:

Local Pin 1 crosses over to Remote Pin 3

Local Pin 2 crosses over to Remote Pin 6

Local Pin 3 crosses over to Remote Pin 1

Local Pin 6 crosses over to Remote Pin 2

Two cables down, one to go! To connect that laptop directly to a switch, we’ve got to be careful of two things:

Using the right cable
Connecting the right cable to the right port on the switch

The cable we need is a rollover cable. All eight wires in the cable will “roll over” to another pin at the remote end, with the wire on Pin 1 at one end rolling over to Pin 8 at the other end, the wire on Pin 2 at one end rolling over to Pin 7 at the remote end, and so forth.

You may also need an adapter for your rollover cable, since one end of the cable is a DB-9 connector, and few if any of today’s laptops have such a port. You probably do have USB ports on your laptop, and you can get an adapter that allows you to connect a rollover cable to your laptop’s USB port from just about any cable dealer.

As for the connection to the switch, you need to make sure you connect the RJ-45 connector on the other end of the rollover cable to the Console port of the switch.

With the proper combination of rollover, straightthrough, and crossover cables, you’re on your way to total network connectivity - and on the way to passing your Cisco CCENT and CCNA exams, too!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free Cisco CCNP, BSCI, ONT,ISCW, and BCMSN exam and CCNA tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages. You can also visit his blog, which is updated several times daily with new Cisco certification articles, free tutorials, and daily CCNA / CCNP exam questions! For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Pass your CCENT and CCNA 640-802 exam with The Bryant Advantage!

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by Chris Bryant, CCIE #12933
Throughout my CCENT and CCNA exam tutorials, you’ll notice these two curious commands on the console port:

line con 0

exec-timeout 0 0

logging synchronous

I’ve been recommending these commands for years to CCNA and CCNP candidates putting their own home labs together, but they can come in handy on the job as well. Let’s take these commands one at a time, starting with the logging synchronous command.

When the router wants you to know something, it wants you to know right now. If the router sends a message to the console while you’re entering a config, by default the router will interrupt your work to show you that message.

In the following example, I opened a Serial interface, which will always result in at least two messages relating to the physical and logical state of the interface. I started typing a sentence immediately after I opened the interface to show you what happens. I’ve bolded the sentence I was entering.

R1(config)#int s0

R1(config-if)#no shut

R1(config-if)#^Z

R1#so here i am

4d04h: %SYS-5-CONFIG_I: Configured from console by consoletyp

4d04h: %LINK-3-UPDOWN: Interface Serial0, changed state to uping and

4d04h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to upi’ve been interrupted quite badly!

4d04h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down

This may seen trivial, but when you have a long command entry interrupted by a console message, you’ll wonder how to prevent that from happening. (After you stop yelling at the router, that is.) By configuring the logging synchronous command on the console port, you’re telling the router to hold such messages until it detects no input from the keyboard and no other output from the router, such as a show command’s output.

R1(config)#line console 0

R1(config-line)#logging ?

synchronous Synchronized message output

The second command I always enter on the console port of a home lab router or switch is exec-timeout 0 0. This disables the default inactivity timeout of 5 minutes and 0 seconds. If you want to change that timer rather than disabling it, the first number represents the number of minutes in the inactivity timer and the second number is the number of seconds.

R1(config)#line con 0

R1(config-line)#exec-timeout ?

<0-35791> Timeout in minutes

R1(config-line)#exec-timeout 0 ?

<0-2147483> Timeout in seconds

R1(config-line)#exec-timeout 0 0 (disables the inactivity timer)

This command can also be configured on the VTY lines to set or disable the inactivity timer for Telnet and SSH users. Here, we’ll set the VTY line inactivity timer to 10 minutes.

R1(config)#line vty 0 4

R1(config-line)#exec-timeout ?

<0-35791> Timeout in minutes

R1(config-line)#exec-timeout 0 ?

<0-2147483> Timeout in seconds

R1(config-line)#exec-timeout 10 ?

<0-2147483> Timeout in seconds

R1(config-line)#exec-timeout 10 0

Some network admins hate these commands, and I personally don’t like to disable my router’s Telnet and SSH inactivity timers. They’re great commands for your present or future home lab, and I also recommend you know them for your CCENT and CCNA exams!

The logging synchronous and exec-timeout commands are helpful in Cisco CCNA and CCNP home labs, but you should also know them for your CCENT and CCNA exams. Learn the details from Chris Bryant, CCIE #12933.

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by Chris Bryant, CCIE #12933
As network admins, we’re going to be primarily concerned with the first three layers of the OSI model - but for the CCENT and CCNA exam, we need to be concerned with all seven!

The OSI layers are often referred to by numbers, with the Application layer being Layer 7 (”L7″), the Presentation layer being Layer 6, and so forth all the way down to Layer 1, the Physical layer. To get you used to that, I’ll refer to the layers by their names and numbers throughout these tutorials.

The Application Layer

This is the layer where the end users themselves interact with the network. Authentication services also run at Layer 7.

Protocols and services that run at L7 include:

Email protocols SMTP and POP3

Telnet

HTTP

File Transfer Protocol (FTP)

Simple Network Management Protocol (SNMP)

The Presentation Layer

This layer answers one simple question: “How should this data be presented?” In addition to properly formatting data, encryption occurs at this layer.

The Session Layer

Layer 5 is the “manager” of the two-way communication between two remote hosts. This is the layer that handles the creation, maintenance, and teardown of communications between those two hosts.

The Transport Layer

TCP and UDP both run at the Transport layer, and we’ve got to know both of those protocols inside and out to pass the CCNA and CCENT exams. We’ll look at those protocols in a future tutorial.

The Network Layer

It’s at Layer 3 of the OSI model that you and I as network admins begin to have a great deal of interaction with the network. Internet Protocol (IP) runs at this layer, and since routers operate here at L3, this layer is often called “the routing layer”.

In a nutshell, routing is a two-question process:

What valid paths exist from the local router to a given destination?

What is the best path to take to get there?

The Data Link Layer

Switches operate at Layer 2, as do Wireless Access Points (WAPs). We’ve got four major specifications that run here, some of which you may already be familiar with:

Ethernet

High Data Link Control (HDLC)

Point-to-Point Protocol (PPP)

Frame Relay

The Physical Layer

When things get a little complicated in networking, I like to remind myself that “it’s all ones and zeroes!” Whatever data our end users are creating, it’s going to eventually be “translated” into a series of 1s and 0s. Once that is done, it’s the Physical layer that handles the actual data transmission. Anything to do with a physical cable - the pins, the connectors, the electrical current itself - is running at the Physical layer.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free Cisco CCNP, BSCI, and BCMSN training and CCNA 640-802 tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages. You can also visit his blog, which is updated several times daily with new Cisco certification articles, free tutorials, and daily CCNA / CCNP exam questions! For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Pass your Cisco CCENT and CCNA 640-802 exam with The Bryant Advantage!

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by MindGenies the e-magician
There are many SSL Certification Authorities with Browser based security for Intra-Organizational security. As companies become more decentralized, they find themselves with employees all over the country and around the world. This presents a challenge for network managers - how to make their networks accessible for their staff as well as maintain reliable security measures. Network managers set up Virtual Private networks to achieve this task. Basically VPN’s let you turn the Internet into your corporate network. Through the use of encryption, VPN connections are protected from outside users, safeguarding data and allowing the secure, remote use of important applications. SSL Certificates help you secure your VPN connections in the easiest way.

SSL Certificates are based on the SSL (Secure Sockets Layer) protocol. SSL is a protocol for managing the security of message transmission on the Internet. The SSL standard is not a single protocol, but rather a set of accepted data transfer routines that are designed to protect the integrity of transmitted messages. SSL relies on certificates - digital identification - and keys. Certificates include the name of the certificate authority that issued the certificate, the name of the entity to which the certificate was issued, the entity’s public key, and time stamps that indicate the certificate’s expiration date.

Thus, if you have a large employee base which is spread across, you should consider SSL Certificates as a good means to secure your internal communications. The SSL VPN can be a good choice for schools, libraries and public kiosks where trust can be an issue but easy access is also important. Applications include Web-based e-mail, business and government directories, databases for educational institutions, file sharing, remote backup, remote system management and consumer-level e-commerce.

http://www.sslgenie.com, SSLGenie (Global Certification Authority) is a leading Internet security expert and provides E-commerce Security Solutions. It offers Flash SSLGenie and Premium SSLGenie which cater to all kinds of industry segments. Flash SSLGenie is the entry level domain validated certificate, while Premium SSLGenie refers to the high assurance, high warranty, and the complete business validated certificate.

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by learningsteps.com
With the upsurge of the internet and the need for continuing education and training a niche arose in the market for instituitions to deliver content and training over the internet. These organizations created online portals of information and courses covering topics such as IT, Personal Development, Human Resources and Businnes Sklls.
These educational portals are central resources for the delivery of Online Computer Training and Business Skills training to the internet community, offering everything from reporting to assements.

So why use Online Training:

* Online Training is convenient and flexible, you can take courses anytime, work, home etc. Online Training provides people with an outlet to enjoy a better work life balance, while still learning.

* Distance Learning provides people who are travelling a lot with information on demand, if they need to learn something new they can just login and start learning.

* Training provided through Online Learning is cheaper, in fact its over 90% cheaper than instructor led courses.

* These websites are usually easy to use, all you need is an internet browser. The courses have bookmarks, help sections, tips and tricks and much more. Navigation is simple.

* The course material is usually highly relevant, information that is not required is usually abstracted. The content is clear and precise.

* You should use e-learning because theirs an old adage Knowledge is Power. The knowledge you have the more oppurtunities will come your way, beside that e-learning is fun and easy to use.

* E-learning is interactive by its nature, courses have simulations (graphical simulations of how to do things) and assessments.

* E-learning courses are usually assessment driven, provides a way of tracking your progress. If you notice your progress is not good you can go back and start that lesson again.

Author: Fergal Dalton : LearningSteps.com

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