Exam Review
640-821: The CCNA in Two-Part Harmony
by Andy Barkl
8/27/2003 -- A new path to Cisco Systems' CCNA, 640-821 allows you to achieve certification in two small steps instead of one giant leap. You can now choose which path to take in obtaining your CCNA. You can pass a single exam, 640-801, reviewed here. Or you can tackle two tests: 640-811, the new ICND (Interconnecting Cisco Networking Devices) exam (reviewed here), and 640-821, INTRO.
I took 640-821, the first of the two that Cisco suggests you tackle, and received 50 questions in 90 minutes with a passing score of 867. Even though this was the beta version of this exam, a screen appeared prior to the test, which said, "This beta exam is in the late stages of development and a score report will be provided." I received a traditional score report, unlike any other beta I've ever taken.
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Exam |
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#640-821: Introduction to Cisco Technologies (INTRO) |
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Vendor |
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Cisco |
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Status |
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Scheduled to go live shortly. Will be available at Pearson Vue and Prometric testing centers worldwide. |
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Reviewer's Rating |
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"This new exam will test your knowledge of basic router configuration, cable types, IOS commands, the OSI model and subnetting." |
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Test Information |
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55 to 65 questions, 60 minute time limit. Cost: $100 (U.S.). |
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Who Should Take This Exam? |
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Candidates for CCNA; must take in conjuction with 640-811 ICND exam. |
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Test Objectives |
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Click here |
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I had three router simulators, many multiple choice questions and a few drag-and-drop items on my exam. Having taken the CCNA 407, 507, 607 and 801 exams, I found this exam much easier. It includes all my favorite topics; cable types, IOS commands, the OSI model and subnetting.
The exam engine is slow when it comes to switching between the simulator-based questions and the standard multiple choice questions. Patience is a must! For most simulator-based questions, you're presented with a router requirement and required to configure one or more routers and save and verify your work. The simulator behaves very much like the real thing and includes limited support for abbreviated, editing and help commands.
The main topics from the objectives list are: Design and Support, Implementation and Operation and Technology. Exam topics include: Network Types, Network Media, Switching Fundamentals, TCP/IP, IP Addressing and Routing, WAN Technologies, Operating and Configuring IOS Devices, and Managing Network Environments. In this article, I address many of these topics under their main headings to help you prepare for this exam.
Design and Support
Under this general heading you'll find these topics: Use a subset of Cisco IOS commands to analyze and report network problems; use embedded layer 3 through layer 7 protocols to establish, test, suspend or disconnect connectivity to remote devices from the router console; and determine IP addresses.
Knowing the basic Cisco Internetworking Operating System commands has traditionally been up to one-third of the required knowledge for the aspiring CCNA. You should become conversant with the commands listed in Table 1.
Table 1. Basic IOS commands used to establish, test, suspend or disconnect connectivity to remote devices from the router console.
Show version |
Display the IOS version and configuration register value |
Show ip interface |
Display the IP address and subnet mask for an interface |
Show running-config |
Display the contents of RAM |
Show startup-config |
Display the contents of NVRAM |
Resume session |
Connect to an existing telnet session from the router's console |
Exit |
Leave a remote or local telnet or console session |
Ping ip address |
Test connectivity |
Traceroute ip address |
Test path connectivity |
Telnet ip address |
Create remote connection |
Tip: When interpreting the output of the ping command, exclamation points (!!!!!) represent echo replies and good connectivity.
Remember your OSI layer assignments for this exam. Ping and tracert are Network layer (3) commands; telnet operates at the Application layer (7).
Implementation and Operation
Under this general heading you'll find these topics listed: establish communication between a terminal device and the router IOS and use the IOS for system analysis; manipulate system image and device configuration files; perform an initial configuration on a router and save the resultant configuration file; use commands incorporated within the IOS to analyze and report network problems; assign IP addresses; describe and install the hardware and software required to be able to communicate via a network; and finally, use embedded data link functionality to perform network neighbor discovery and analysis from the router. Sounds like it's time for another table of commands!
To establish connectivity between a terminal device and the router's IOS, use an ASCII-compliant terminal-emulation program such as HyperTerminal or Telnet.
Type the console or VTY line password for user access or enable and the enable password for executive access.
See Table 2 below for IOS commands needed to manage connections, images and CDP.
Table 2. IOS commands for system analysis, manipulating system image and device configuration files, performing an initial configuration on a router and saving the resultant configuration file, use commands incorporated within IOS to analyze and report network problems and assigning IP addresses.
Show users or sessions |
Display a list of connected users or open sessions to the router's IOS |
Copy TFTP Flash |
Manipulate the system image (IOS) in flash memory |
Config terminal |
Allow changes to the configuration file stored in RAM |
Line VTY 0 4, password password |
Configures telnet password |
Line console 0, password password |
Configures console line password |
Copy running-config startup-config |
Save those changes to NVRAM |
Interface interface name address mask |
Assign IP address and mask to a router's interface |
Show CDP |
Display Cisco Discovery Protocol (a layer 2 protocol) running configuration. |
Tip: The boot system flash command configures the router's IOS to look for the IOS image in flash memory.
Technology
Under the final heading of Technology in the exam guide, you'll find a multitude of topics. Let me address them by providing my list of "things to know."
First, binary, hex and decimal are all numbering systems you should be intimately familiar with for this exam. Table 3 provides a conversion chart.
Table 3. Binary, hex and decimal conversions.
Binary |
Hex |
Decimal |
0000 |
0 |
0 |
0001 |
1 |
1 |
0010 |
2 |
2 |
0011 |
3 |
3 |
0100 |
4 |
4 |
0101 |
5 |
5 |
0110 |
6 |
6 |
0111 |
7 |
7 |
1000 |
8 |
8 |
1001 |
9 |
9 |
1010 |
A |
10 |
1011 |
B |
11 |
1100 |
C |
12 |
1101 |
D |
13 |
1110 |
E |
14 |
1111 |
F |
15 |
Computer network LAN topologies consist of bus, star and ring. In a bus and star network topology, data travels from end to end. In a ring topology, data travels in a ring. WAN topologies cover greater geographic distances and all data travels in a bit-by-bit serial fashion.
Tip: Data transmission flow control occurs with the help of buffering, windowing and congestion avoidance.
In token ring networks, a token is passed around the network from device to device. When a device has data to send, it must wait until it has the token before sending its data.
Tip: To connect a network device to any one of these network types, you need at a minimum a compatible network interface card and a connecting cable and protocol.
Network media includes wireless, twisted-pair and optical. Wireless uses no physical connectors. Twisted-pair is still the most common. UTP (Unshielded Twisted Pair) includes eight wires in four twisted pairs. Optical media includes fiber, which offers the greatest distance of the three types. Table 4, below, shows the most common of the twisted-pair wiring configurations.
Table 4. Common wiring configurations.
Type
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Use
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Pin-Out
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Straight-thru
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workstations connecting to hubs, switches, routers
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1-----1
2-----2
3-----3
4-----4
5-----5
6-----6
7-----7
8-----8
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Crossover
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workstation to workstation or hub to hub and switch to switch
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1-----3
2-----6
3-----1
4-----4
5-----5
6-----2
7-----7
8-----8
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Rolled
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workstation's serial port to router console port
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1-----8
2-----7
3-----6
4-----5
5-----4
6-----3
7-----2
8-----1
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Tip: Routers are responsible for switching and routing of data packets.
Additional Information |
Loads of resources on the market will help you prepare and practice for passing the CCNA exams. One such favorite resource of mine is free, authoritative and recommended by many others: Cisco.com.
Once at Cisco.com, you'll want to spend time with the reference guides and technology white papers available in the documentation site or CCO (Cisco Connection Online) found here.
For the first set of exam objectives, I recommend the "Internetworking Technology Handbook" chapters 1-7 found here. Honestly, how much easier and cheaper can it get? This resource will help you keep the costs of your studies down (along with many other recommendations in the "IT Certification on the Cheap" guide sold here).
When deciding which study guides will prepare you for the new CCNA 640-821 exam, keep in mind that the exam objectives are only a subset of the exam. If you've already started your studying using one of the many popular 607 study guides on the market, you should be able to match the objectives from this exam to chapters in your book. For example, in Cisco Press' Cisco CCNA Exam #640-607 Certification Guide (ISBN 1-58720-055-4), you should study chapters 1-6 for this exam and the remainder (7-13) for the companion ICND 640-811 exam.
You should also pick up a router simulator or real router to prepare for the router simulator questions. Cisco uses a router simulator in their exams developed by the Cisco Networking Academy program. It also offers a sample on its Web site. Many third-party products on the market are similar. You can view and even demo a copy of the official Cisco exam simulator here.
Last, spend a few minutes reviewing "My Top 10 Study Tips for Cisco's 640-607 CCNA Exam" by Karen Robertson-Kidd, found here. - A.B.
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Cisco routers include the following hardware and software components: CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), NVRAM (Non-Volatile RAM), IOS, mini-IOS and configuration files. A router startup process is like this:
- Bootstrap loads from ROM.
- Router finds IOS, usually from flash, and loads it.
- Router finds and loads configuration file, usually from NVRAM.
Ethernet uses CSMA/CD for error detection and correction. It includes the following:
How could any network student understand networking without knowing the OSI model? The OSI 7 layer reference model includes these layers, taking it from the top: Application, Presentation, Session, Transport, Network, Data Link, and Physical. The numbering starts from the bottom (physical layer is number 1). Knowing the layer names and their order is crucial. Some people like to use an anagram to help. One of my favorites (from the bottom up): Please Do Not Throw Sausage Pizza Away.
Knowing where the most common network devices operate in the OSI model is also a must. At the physical layer there is the cabling of the network, repeaters and hubs. The data link layer includes bridges and switches, and routers operate at the network layer.
Tip: A switch is really nothing more than a multi-port bridge.
Understanding protocol operation and at which layer each functions is an exam requirement. This exam focuses only on TCP/IP. From the physical layer up, there are protocols that define the physical connection and signaling on the wire such as V.35 and RS-232. At the data link layer there are also protocols responsible for defining the network topology and data communication standards such as ethernet, token-ring, and FDDI.
At the network layer, there's IP, ICMP, ARP. At the transport layer, there's TCP and UDP. UDP is fast and efficient but doesn't provide guaranteed delivery and retransmission like TCP. TCP is more commonly used at this layer by many upper-layer protocols and applications.
The Internet protocol suite includes many application-layer protocols that represent a wide variety of applications, including the following:
- FTP (File Transfer Protocol) -- moves files between devices.
- SNMP (Simple Network-Management Protocol) -- reports network conditions and sets network threshold values.
- Telnet -- serves as a terminal emulation protocol.
- SMTP (Simple Mail Transfer Protocol) -- provides electronic mail services.
- DNS (Domain Name System) -- translates the names of network nodes into network addresses.
- TFTP (Trivial File Transfer Protocol) -- allows for transfer of router files to and from a network workstation.
Table 5, below, lists the common application-layer protocols, their use of TCP or UDP and port number assignments.
Table 5. Common application-layer protocols, TCP or UDP, and port numbers.
Protocol |
TCP or UDP |
Port Number |
FTP |
TCP |
20 and 21 |
SNMP |
UDP |
161 |
SMTP |
TCP |
25 |
DNS |
TCP and UDP |
53 |
TFTP |
UDP |
69 |
Cisco requires you to know how to plan, assign, configure, subnet and troubleshoot IP addresses. A popular resource recommended by many for learning how to subnet is http://www.LearnToSubnet.com.
For this exam, you must have an understanding of the classes of IP addresses, their starting and ending ranges, default subnet masks, the minus-2 rule, how to figure and identify the first host, last host and broadcast address of any subnet, along with calculating the mask for a required number of networks or hosts or both.
Tip: Here's a technique to help calculate the subnet: 256 minus the subnet mask. For example; the address 192.168.0.22 255.255.255.240, is on the 192.168.0.16 subnet with subnets of 16, 32, 48, and so on. The first assignable address is 17, and the broadcast is 31.
That wraps it up for this exam review. If, after reading this review, you find you're not ready to prepare for the Cisco exams, consider Network+, the entry-level test put out by CompTIA. (You can find the objectives here.)
New Self-Study Books Out by Cisco Press |
Cisco Press, a partnership between Cisco Systems and Pearson Education, has released several new books intended for self-study on the new CCNA exams.
CCNA ICND Exam Certification Guide (ISBN 1-58720-083-X) and CCNA INTRO Exam Certification Guide (ISBN 1-58720-094-5) both retail for $39.95. Both run about 600 pages and are written by Wendell Odom, a CCIE who teaches for Skyline Computer. You can buy a two-volume library (ISBN 1-58720-095-3) that includes both books for $59.95.
The first book, INTRO, encompasses networking fundamentals, the operation of Cisco devices, LAN switching (the basics, including cabling and standards), TCP/IP (specifically IP addressing and subnetting, basic router configuration and an introduction to dynamic routing protocols), as well as remote access technologies.
The second book, ICND, covers LAN switching, TCP/IP, WANs (specifically, leased lines, ISDN and frame relay) and network security.
The volumes provide open ended questions at the end of each chapter, as well as a simulated exam on a CD. If you lack practice equipment, the CD also includes a version of Boson Software's NetSim, network simulation software with several lab exercises and lab scenarios.
No doubt, other publishers (particularly Sybex) will release competitive titles to help you prepare for the CCNA exams. Those titles will round out your understanding of the technology. But these two volumes are a sound place to begin your studies. - D.S.
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Cisco certification is a good way to gauge your understanding of networking and internetworking at the lower levels of the OSI reference model. It can also be the jumpstart you need to tackle other certifications, which are highly valued by employers and constantly push you to excel in your understanding of Cisco technologies and products. Good luck!
Have you taken this exam? Post your rating below!
Andy Barkl, CCNP, CCDP, CISSP, MCT, MCSE:Security, MCSA:Security, A+, CTT+, i-Net+, Network+, Security+, Server+, CNA, has over 19 years of experience in the IT field. He's the owner of MCT & Associates LLC, a technical training and consulting firm in Phoenix, Arizona. He spends much of his time in the classroom but has also been responsible for many Microsoft Windows 2000, Exchange 2000, and Cisco networking deployments for many clients across Arizona. He's also the online editor for MCPMag.com, TCPMag.com, CertCities.com, and a contributing author and editor for Sybex and Cisco Press. He hosts a multitude of exam preparation chats monthly on MCPmag.com, TCPmag.com and CertCities.com. You can reach him at .
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