March 20th, 2009 at 09:19pm
Under Certification
IP Addressing
An IP address is a unique logical identifier for a node or host connection on an IP network. IP address is a 32 bit binary number, and represented by 4 decimal values of 8 bits each. The decimal values range from 0 to 255. This is known as dotted decimal notation.
Example: 192.189.210.078
It is sometimes useful to view the values in their binary form.
Dotted decimal representation: 192 .189 .210 .078
Binary representation: 11000000.10111101.11010010.1001110
Every IP address consists of network identifier and node identifier. The IP network is divided based on Class of network. The class of network is determined by the leading bits of the IP address as shown below.
Address Classes
There are 5 different address classes. You can determine which class any IP
address is in by examining the first 4 bits of the IP address.
Class A addresses begin with 0xxx, or 1 to 126 decimal.
Class B addresses begin with 10xx, or 128 to 191 decimal.
Class C addresses begin with 110x, or 192 to 223 decimal.
Class D addresses begin with 1110, or 224 to 239 decimal.
Class E addresses begin with 1111, or 240 to 254 decimal.
Addresses beginning with 01111111, or 127 decimal, are reserved for loopback and for internal testing on a local machine. Class D addresses are reserved for multicasting. Class E addresses are reserved for future use. They should not be used for host addresses.
Now we can see how the Class determines, by default, which part of the IP address belongs to the network (N) and which part belongs to the Host/node (H).
Class A: NNNNNNNN.HHHHHHHH.HHHHHHHH.HHHHHHHH
Class B: NNNNNNNN.NNNNNNNN.HHHHHHHH.HHHHHHHH
Class C: NNNNNNNN.NNNNNNNN.NNNNNNNN.HHHHHHHH
In the example, 192.189.210.078 is a Class C address so by default the Network part of the address (also known as the Network Address) is defined by the first three octets (192.189.210.XXX) and the node part is defined by the last one octets (XXX.XXX.XXX.078).
In order to specify the network address for a given IP address, the node section is set to all 0s. In our example, 192.189.210.0 specifies the network address for 192.189.210.078. When the node section is set to all 1s, it specifies a broadcast that is sent to all hosts on the network. 192.189.210.255 specifies the broadcast address.
Private Subnets
There are three IP network addresses reserved for private networks. The addresses are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. They can be used by anyone setting up internal IP networks, such as an intranet. Internet routers never forward the private addresses over the public Internet.
Vijayanand has done his post graduation (M.E.) in Communication Systems. He has several years of experience in electronic assembly and design, rf testing, and networking. He is a Cisco Certified Networking Professional, and an MCSE (Microsoft Certified Systems Engineer). Complete tutorial on CCNA is available at SimulationExams.com
Author: Vijayanand Yadla
Keywords: ip,addressing,address mask, ip addressing
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By admin
March 20th, 2009 at 09:19pm
Under Certification
Information Technology Schools prepare students for computer-related professions with the knowledge, skills, and experience needed for a professional career.
Programs in Information Technology (IT) make it possible to earn Bachelor of Science (BS), Master of Science (MS), and Doctorate in Computer Science (DCS) degrees. Degree programs offer concentrations in various areas of IT to meet demands of the industry and to impart qualifications that contribute to organizational productivity and success.
Students are provided with good basic understanding of business fundamentals, rudiments of Information Technology, and applications of IT to modern business that promote success and build careers in the IT industry. Information Technology Schools offer degrees with concentrations designed to prepare students with high levels of knowledge for careers in IT as computer information systems managers, operations research analysts, and management and data analysts.
Students in Information Technology programs can expect courses in project management theory, information systems, database systems, computer programming, network systems, systems security, and e-business. Some Information Technology Schools offer the benefit of adding professional certifications as the student progresses through IT programs of study. Certificates in these programs build student resumes by enhancing skills in management, accounting, finance, global business, human resources, and project planning, among others.
Some Information Technology Schools offer dual degree programs that enrich career options with minimal additions to coursework. Students can upgrade their IT degrees with concentrations in software systems engineering, security, network management, and others. A business administration degree can be markedly enhanced with concentrations in areas of Information Technology.
If you would like to learn more about Information Technology Schools or Online Information Technology Schools, you can find more in-depth information and resources on our website.
DISCLAIMER: Above is a GENERAL OVERVIEW and may or may not reflect specific practices, courses and/or services associated with ANY ONE particular school(s) that is or is not advertised on SchoolsGalore.com
Copyright 2006 - All Rights Reserved Michael Bustamante, in association with Media Positive Communications, Inc. for SchoolsGalore.com
Notice to Publishers: Please feel free to use this article in your Ezine or on your Website; however, ALL links must remain intact and active.
Michael Bustamante is a staff writer for Media Positive Communications, Inc. in association with SchoolsGalore.com. Visit our Traditional School Directory and find Colleges, Universities, Vocational Schools, and Online Schools at SchoolsGalore.com, your educational resource to locate schools.
Author: Michael Bustamante
Keywords: information technology schools, IT training, computer schools, colleges, education, university, degr
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By admin
March 20th, 2009 at 09:19pm
Under Certification
The ISO OSI model are explained below. The seven layers of the OSI model are:
- Application
- Presentation
- Session
- Transport
- Network
- Antiqua>Data Link
- Physical
1 Application layer:
This layer provides a means for the user to access information on the network through an application. Many user applications that need to communicate over the network interact with the Application layer protocol directly. The user applications are not part of OSI Application layer, use the networking services offered by the networking protocol suite. Application layer functions typically include identifying communication partners, determining availability of required resources. Some examples of application layer implementations include Telnet, File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP).
2 Presentation layer:
Presentation layer converts local host computer data representations into a stard network format for transmission on the network. On the receiving side, it changes the network format into the appropriate host computer’s format so that data can be utilized independent of the host computer. ASCII EBCDIC conversions, cryptography, the like are hled here. Examples of Presentation layer coding conversion schemes include common data representation formats, conversion of character representation formats, common data compression schemes, common data encryption schemes.
Presentation layer implementations are not typically associated with a particular protocol stack. Some well-known stards for video include QuickTime Motion Picture Experts Group (MPEG). QuickTime is an Apple Computer specification for video audio, MPEG is a stard for video compression coding.
3. Session layer:
The session layer establishes, manages, terminates communication sessions. Communication sessions consist of service requests service responses that occur between applications located in different network devices. These requests responses are coordinated by protocols implemented at the session layer. Some examples of session-layer implementations include AppleTalk’s Zone Information Protocol (ZIP), Decent Phase Session Control Protocol (SCP).
4.Transport layer:
Transport layer is responsible for providing reliable service between the hosts. Upper layer datagrams are broken down into manageable datagrams then appropriate header information (such as sequence number, port number, etc.) is added to the datagram before passing it on to the Network layer. Two frequently used transport protocols are the TCP (Transmission Control Protocol) the UDP (User Datagram Protocol).
Important features of Transport layer:
- Transport layer ensures reliable service.
- Breaks the message (from sessions layer) into smaller datagrams, appends appropriate unit header information.
- Responsible for communicating with the Session layer
Important features of TCP/UDP:
- TCP/IP widely used protocol for Transport/Network layers
- TCP: (Transport Control Protocol) TCP ensures that a packet has reached its intended destination by using an acknowledgement. If not, it retransmits the lost messages. Hence, TCP is called a connection oriented protocol.
- UDP (Universal Data gram Protocol): UDP simply transmits packets over the internet. It does not wait for an acknowledgement. It is the responsibility of upper layer protocols to ensure that the information had reached the intended partner(s). Hence, UDP is often called connectionless protocol.
- Application programs that do not need connection-oriented protocol generally use UDP.
5. Network layer:
Network layer is responsible for the routing of packets through the entire network. The layer uses logical addressing for this purpose. Note that the physical address (like MAC address) keeps changing from hop to hop when a packet travels from source to destination. As a result, an address that doesn’t change is required to ensure continuity between hops. This is nothing but logical address. For IP networks, IP address is the logical address; for Novell network, IPX address is the logical address, so on. This layer also provides for congestion control, accounting information for the network. IP (Internet Protocol) is an example of a network layer protocol.
6. Data link layer:
Data link layer provides delivery of information frames between communicating partners. This layer is responsible for flow regulation, error detection correction, framing of bits for transmission. The network data frame is made up of checksum, source address, destination address, the data itself. The largest frame size that can be sent is known as the maximum transmission Unit (MTU).
Important features of Data link layer:
- Assembles bits into frames, making them ready for transmission over the network.
Provides error detection, correction to transmitted frames. If the checksum is not correct, it asks for retransmission. (Send a control message).
Consists of two sub layers:
Logical Link Control (LLC): Defines how data is transferred over the cable provides data link service to the higher layers.
Medium Access Control (MAC): Controls media access by regulating the communicating nodes using pre-defined set of rules. (i.e. Token passing, Ethernet [CSMA/CD all have MAC sub-layer protocol).
Different Data link layer protocols define different network protocol characteristics, including physical addressing, network topology, error notification, sequencing of frames, flow control. Physical addressing (as opposed to logical addressing) defines how devices are addressed at the data link layer. The protocols used in Data link layer are SLIP, PPP, CSLP.
7. Physical layer:
This is the bottom-most layer of the OSI model. The Physical layer hles the bit-level communications across the physical medium. The physical medium could be made up of wired electrical signals, or light, or radio (wireless) signals. Physical layer specifications define characteristics such as media, data rates, maximum transmission distances, physical connectors.
Some of the important stards that deal with physical layer specifications are:
RS-232(for serial communication lines), X.21, EIA 232, G730.
Physical layer Data link layer implementations can be categorized as either LAN or WAN specifications.
Vijayan has done his post graduation (M.E.) in Communication Systems. He has several years of experience in electronic assembly design, rf testing, networking. He is a Cisco Certified Networking Professional, an MCSE (Microsoft Certified Systems Engineer). He is a director of An Software Training Pvt. Ltd. Complete tutorial on Networking is available at SimulationExams.com
Author: Vijayan Yadla
Keywords: Seven Layers of OSI model -An Overview.
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By admin
March 20th, 2009 at 09:19pm
Under Certification
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.
Packet switching may sound a little odd, but it’s a very efficient way of transporting data. Frame Relay is a packet switching technology, as is X.25, and both of these protocols are highly efficient.
If we have packets that must arrive at the destination in the same order in which they left the source, packet switching isn’t a good choice. For this situation, we’ll need to use some form of circuit switching, and we’ll discuss that in tomorrow’s Cisco CCNA certification training article!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!
Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, How To Pass The CCNA, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Author: Chris Bryant
Keywords: isco/new?tag=day2soft-20′title= ‘cisco: Newly tagged products at Amazon.com’>cisco, ccna, certification, exam, training, prep, what, is, packet, switching, frame, relay, router
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By admin
March 20th, 2009 at 09:19pm
Under Certification
The Computing Technology Industry Association (CompTIA) is a trading group offering A+ to validate the skills of students that want to apply as computer professionals because it is a vendor-neutral highly recognized by hardware software vendors, distributors resellers.
CompTIA s are awarded after taking two different exams, complementary to each other - the A+ DOS/Windows exam that requires A+ training the A+ Core Exam. In order to prepare your A+ Certification Exams, you need to master the basics in computer services.
Skills which are tested include the student’s ability, performing a number of different tasks, including basic networking, installation, configuration, diagnose preventive maintenance. However, CompTIA s require knowledge in other areas, which are covered by A+ training, such as network security safety.
A+ is also used by companies for testing purposes, in order to find out knowledge, communication professionalism of their employees. A+ training ensures employers that potential cidates to a job position are knowledgeable, having the right skills required to support the companies’ need.
If you are willing to apply for am A+ Certification, get ready for the exams by following these simple steps:
CompTIA A+ Certifications are prepared with the exam objectives in mind. CompTIA will provide you with the objectives for the available A+ exams.
After getting your objective, find the materials for the A+ training, based on the CompTIA Approved Quality Curriculum (CAQC), which are one of the most easy to learn materials available to IT professionals students looking for A+ .
Other materials that you can obtain are available at Press, including a guide (courseware) created expressly for people enrolled in CompTIA s. Once you get this material, you are ready for the next step: find A+ training providers.
A+ providers receive a seal of recognition for quality awarded by CompTIA Learning Alliance (CLA), after receiving special training in order to offer CompTIA exams.
Chosen the provider, get sample test questions to help you practice. Overview question answers is a good option to prepare for your exams, this samples are available at CompTIA website.
Studying hard, taking tips testing your skills are useful aids to earn your A+ . When you are ready for the exams, look for financial aid if necessary before purchasing your CompTIA A+ Exam Voucher.
There are numerous financial resources compiled by CompTIA for students, employers US military, who want to obtain A+ training. With your voucher, you can register for your exam at the nearest testing center where CompTIA s are available.
Natalie ara writes on education, learning . The Computing Technology Industry Association (CompTIA) is a trading group offering A+ to validate the skills of students that want to apply as computer professionals because it is a vendor-neutral highly recognized by hardware software vendors, distributors resellers. A+ training ensures employers that potential cidates to a job position are knowledgeable, having the right skills required to support the companies’ need.
Author: Natalie Ara
Keywords: A+ Certification Exams
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By admin
March 20th, 2009 at 09:19pm
Under Certification
Cisco CCNA certification training includes troubleshooting your own work and that of others. The best CCNA certification 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 CCNA certification topics - Frame Relay and routing protocols.
A student was working on his 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:
frame-relay map ip 172.12.123.2 122
frame-relay map ip 172.12.123.3 123
He was able to ping both spokes from the hub, so he assumed everything was working correctly. Then he configured RIP version 2 on the router and got the following result after running debug ip rip and clearing the routing table with clear ip route *:
03:33:01: IP: s=172.12.123.1 (local), d=224.0.0.9 (Serial0), len 72, sending broad/multicast
03:33:01: IP: s=172.12.123.1 (local), d=224.0.0.9 (Serial0), len 72, encapsulation failed
You may have already spotted the problem, and if you did, your CCNA certification exam studies are going well! The problem is that the broadcast option was left off the frame map statements. broadcast must be configured on frame map statements in order to send broadcasts and multicasts across the frame link. As you know from your CCNA certification exam studies, RIP version 1 broadcasts updates and RIP version 2 multicasts them, so the broadcast option must be present for either version to send updates by using those frame mappings.
He then rewrote the frame map statements as shown below….
R1(config-if)#frame map ip 172.12.123.2 122 broadcast
R1(config-if)#frame map ip 172.12.123.3 123 broadcast
… and the RIP updates went out as expected.
R1#debug ip rip
RIP protocol debugging is on
R1#clear ip route *
06:22:13: RIP: sending general request on Loopback0 to 224.0.0.9
06:22:13: RIP: sending general request on Serial0 to 224.0.0.9
06:22:13: RIP: ignored v2 packet from 1.1.1.1 (sourced from one of our addresses)
06:22:14: RIP: received v2 update from 172.12.123.3 on Serial0
06:22:14: 1.1.1.1/32 -> 0.0.0.0 in 3 hops
06:22:14: 2.2.2.2/32 -> 0.0.0.0 in 2 hops
06:22:14: 3.3.3.3/32 -> 0.0.0.0 in 1 hops
06:22:14: 172.12.23.0/24 -> 0.0.0.0 in 1 hops
06:22:14: 172.12.123.0/24 -> 0.0.0.0 in 1 hops
06:22:14: RIP: sending v2 update to 224.0.0.9 via Loopback0 (1.1.1.1)
06:22:14: 2.2.2.2/32 -> 0.0.0.0, metric 3, tag 0
06:22:14: 3.3.3.3/32 -> 0.0.0.0, metric 2, tag 0
06:22:14: 172.12.23.0/24 -> 0.0.0.0, metric 2, tag 0
06:22:14: 172.12.123.0/24 -> 0.0.0.0, metric 1, tag 0
06:22:14: RIP: sending v2 update to 224.0.0.9 via Serial0 (172.12.123.1)
Cisco CCNA certification depends on noticing details like these, and there’s no better way to learn these details than by working on real Cisco routers and switches. Whether you’re renting rack time online or buying used Cisco routers and switches, real-time debugs and configurations are the way to CCNA certification exam success!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!
Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, How To Pass The CCNA, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Author: Chris Bryant
Keywords: ccna, certification, cisco, test, prep, frame, relay, ping, rip, ospf, protocol, broadcast, training
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March 20th, 2009 at 09:19pm
Under Certification
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 exam, it’s also an excellent example of a packet-switching technology.
In circuit switching, a dedicated path is built between the source and destination, and the packets will all be sent over this dedicated path. If this sounds like a telephone call, you’re right! A phone call is a great example of circuit switching. On a Cisco router, ISDN is a circuit-switching technology.
The deciding factor between circuit switching and packet switching comes down to the tolerance for delay. Not to say that packet switching is slow, but any reassembly takes time. While most packet-switching technologies are cheaper to run than most circuit-switching technologies, that cost is offset by the slight delay inherent to packet switching. For voice and video, circuit switching is the most effective.
Packet switching and circuit switching both have their place in today’s Cisco networks, and don’t be surprised if both topics show up on your CCNA certification exam as well!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!
Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, How To Pass The CCNA, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Author: Chris Bryant
Keywords: ccna, cisco, certification, exam, training, circuit, switching, packet, test, prep, isdn
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By admin
March 20th, 2009 at 09:19pm
Under Certification
CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification is getting a new look at the end of 2006. The BSCI and BCMSN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exams are being updated, and the CIT and BCRAN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exams are being retired. Let’s take a look at what to expect from the new BSCI new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam.
According to Cisco’s new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam blueprint - admittedly a very broad blueprint at this time - the major new topics are IP version 6 (IPv6) and multicasting. The addition of these two topics will make an already demanding Cisco new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam that much tougher, but this is a great change for the new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam and for the candidate. IPv6 is just going to become more and more prevalent in today’s networks, and multicasting is as well.
Multicasting for the Cisco CCNP BSCI new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam is going to go far beyond what you learned about it in your CCNA studies. For the new BSCI new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam, you’ll need to know the different methods of creating multicast groups as well as assigning members to them. This material was previously limited to CCIE-level books, and while I don’t look for the questions to be as hard as the CCIE written new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam, multicasting is not an easy topic and should not be taken lightly by the CCNP candidate in 2007.
One major CCNP new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam topic that isn’t going anywhere is BGP. The Border Gateway Protocol has been a big part of previous BSCI new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exams, and that looks to continue.
If you’re pursuing your CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification in 2007, be sure to monitor Cisco’s website for additions to the CCNP blueprint. It’s obvious that Cisco has raised the bar for CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification, and earning this important Cisco new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification will in turn raise your market value and networking knowledge like never before. Watch for future tutorials new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>examining the other three new CCNP new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exams!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam tutorials, including Cisco CCNA new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!
Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam practice questions! A free 7-part course, How To Pass The CCNA, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Author: Chris Bryant
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March 20th, 2009 at 09:19pm
Under Certification
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 quite 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:
R1 con0 is now available
Press RETURN to get started.
R1>
To get into enable mode, by default all I have to do is type enable.
R1>enable
R1#
See how the prompt changed? By default, I can now run all the show and debug commands I want, not to mention entering global configuration mode and doing pretty much what I want. It just might be a good idea to password protect this mode! We do so with either the enable password command or the enable secret command. Let’s use the enable password command first.
R1(config)#enable password dolphins
Now when I log out and then go back to enable mode - or try to - I should be prompted for the password dolphins. Let’s see what happens.
R1>enable
Password:
R1#
I was indeed prompted for a password. Cisco routers will not show asterisks or any other character when you enter a password; in fact, the cursor doesn’t even move.
The problem with the enable password command is that the password will show in the configuration in clear text, making it easy for someone to look over your shoulder and note the password for future use, as shown below:
hostname R1
!
enable password dolphins
We could use the service password-encryption command to encrypt the enable password, but that will also encrypt all the other passwords in the Cisco router config. That’s not necessarily a bad thing! Here’s the effect of this command on the enable password we set earlier.
enable password 7 110D1609071A020217
Pretty effective encryption! However, if we want to have the enable password automatically encrypted, we can use the enable secret command. I’ll use that command here to set this password to saints, and note that I’m not removing the previous enable password.
R1(config)#enable secret saints
After removing the service password-encryption command, we’re left with two enable mode passwords, and they appear in the Cisco router config like this:
enable password dolphins
enable secret 5 $1$kJB6$fPuVebg7uMnoj5KV4GUKI/
If we have two enable passwords, which one should we use to log into the router? Let’s try the first password, dolphins, first:
R1>enable
Password:
Password:
When you’re prompted for the password a second time, you know you got it wrong the first time! Let’s try saints:
R1>enable
Password:
Password:
R1#
When both the enable secret and enable password commands are in use on a Cisco router, the enable secret password always takes precedence. dolphins didn’t get us in, but saints did. That’s valuable information for both the CCNA certification exam and real-world networks, because there’s no worse feeling than typing a password at a Cisco router prompt and then getting another password prompt!
This is just one way to perform basic Cisco router security with passwords. We’ll take a look at other methods in a future CCNA certification exam training tutorial!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!
Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, How To Pass The CCNA, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Author: Chris Bryant
Keywords: ccna, certification, exam, training, password, cisco, router, network, security, enable, mode
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By admin
March 20th, 2009 at 09:19pm
Under Certification
Cisco CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification is about to become more valuable and more difficult! Cisco is making major new?tag=day2soft-20′title= ‘changes: Newly tagged products at Amazon.com’>changes to the CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification program, retiring two new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exams (BCRAN and CIT) while updating two old friends, the BSCI and BCMSN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam. Today, we’ll take a look at the new?tag=day2soft-20′title= ‘changes: Newly tagged products at Amazon.com’>changes in the Building Converged Cisco Multilayer Switched Networks (BCMSN) new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam.
According to Cisco’s new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam blueprint, there are some major additions with the introduction of the new?tag=day2soft-20′title= ‘642-812: Newly tagged products at Amazon.com’>642-812 new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam. Wireless access, security, and voice are all rapidly growing features and concerns in today’s real-world networks, and Cisco is responding to that by adding all three of these topics to the CCNP BCMSN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam. Cisco CCNP candidates should expect to be questioned on WLANs as well as wireless clients.
There were some security topics on the 642-811 BCMSN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam, port security and 802.1x among them. The successful Cisco CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification candidate will now be expected to know about the different network attacks that can take place at the data link layer of the OSI model, including DHCP Spoofing and VLAN Hopping.
There was also just a bit of voice material on the 642-811 BCMSN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam, but you’ll have to know more voice to pass the new?tag=day2soft-20′title= ‘642-812: Newly tagged products at Amazon.com’>642-812 new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam. Voice VLANs, voice QoS, and IP Phone configuration are just some of the topics being added to the new BCMSN new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam.
Cisco is obviously raising the bar with the new CCNP new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exams, and this new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification is going to be harder to get than ever before. That also makes it more valuable than ever before, and 2007 will be the best year yet in which to earn your CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification. Make your plans to earn this valuable Cisco new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification, and then put that plan into action!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam tutorials, including Cisco CCNA new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!
Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam practice questions! A free 7-part course, How To Pass The CCNA, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Author: Chris Bryant
Keywords: new?tag=day2soft-20′title= ‘cisco: Newly tagged products at Amazon.com’>cisco, new?tag=day2soft-20′title= ‘ccnp: Newly tagged products at Amazon.com’>ccnp, new?tag=day2soft-20′title= ‘certification: Newly tagged products at Amazon.com’>certification, training, new, new?tag=day2soft-20′title= ‘exam: Newly tagged products at Amazon.com’>exam, new?tag=day2soft-20′title= ‘bcmsn: Newly tagged products at Amazon.com’>bcmsn, new?tag=day2soft-20′title= ‘642-812: Newly tagged products at Amazon.com’>642-812, new?tag=day2soft-20′title= ‘changes: Newly tagged products at Amazon.com’>changes, voice, video, switch, stp
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