Date of Issue: 05-01-2001 Routing and Switching CCIE Lab Preparation Guide by David Wolsefer Introduction CCIE Test Nondisclosure Policy CCIE Lab Preparation Blueprint The Cisco Web
Trang 1Date of Issue: 05-01-2001
Routing and Switching CCIE Lab
Preparation Guide
by David Wolsefer
Introduction
CCIE Test Nondisclosure Policy
CCIE Lab Preparation Blueprint
The Cisco Web Site
Exam Description
Further Recommendations
Find a Mentor
Develop Confidence and Self-Control
Time Management
Improving Your Speed
Base Configuration
The Network Diagram
Network Address Planning
Preparing for the Lab Exam
Books to Read
Obtaining a Home Lab
Lab 1 - The Budget Lab
Lab 2 - The Complete Lab
Training Classes
Skills Needed for the CCIE Lab
How to Configure a Router as a Frame Switch
Fully Meshed Frame Switch
Partially Meshed Frame Switch
Configuring a Terminal Server
Configuring A LightStream 1010 ATM Switch
Role of the Proctor
Preparing For Troubleshooting
Obtaining Access to the Routers and Switches
Check Layer 1
Check Layer 2
Check Layer 3
Stress Management
A Final Warning
References
Trang 2Figure 1 The Halifax CCIE Lab
Introduction
When I first went to the CCIE lab, there weren't very many books available and little was known about the CCIE lab, except that the labs had a reputation for being extremely difficult Any regular reader of the Cisco mailing lists at groupstudy.com will often see questions posed to the various lists about the best way to prepare for the CCIE lab such as: "What are the best strategies to use?" "What is the lab like?" "Where should I go to take the lab?" and many more This Tutorial answers these questions within the bounds of Cisco's strong nondisclosure agreement This paper will discuss in detail how I prepared for the CCIE lab in routing and switching and give some lengthy advice about how
to prepare for the lab exam With these thoughts in mind, let's get started!
CCIE Test Nondisclosure Policy
Each CCIE candidate must sign a very strict non-disclosure agreement (NDA) before attempting the exam You can view the non-disclosure agreement by examining the CCIE sections of Cisco's web site It is very important that each candidate adheres to this nondisclosure policy for several reasons I have heard of very dire consequences for those who violate the NDA including the revocation of CCIE status, prohibiting the candidate from attempting the exam
anywhere for a very lengthy time (a year or two), or never allowing the candidate to attempt the exam again There is
a long-term effect of the NDA as well If the CCIE certification is to maintain its reputation and integrity, then each candidate must pass the exam using his/her own skills and abilities The proven ability to perform under pressure is what separates the CCIE from all other certifications and makes it so valuable For these reasons, this paper adheres strictly to this non-disclosure policy Any direct references to the CCIE examination format and content are based on Cisco's publicly available material including the Cisco web site , Networkers CCIE Power Sessions, and public
interviews with Jeff Buddemeier (Cisco's CCIE Program Manager) I will not disclose any material that will violate the NDA that I signed Cisco has a strict non-disclosure policy about all exams, but especially the CCIE lab exam I will in
no way compromise the integrity of the exam or my own CCIE status, please don't you do it either
CCIE Lab Preparation Blueprint
One of the questions I see a lot is whether you should first go for the CCNA or the CCNP before attempting the CCIE
My answer is that it depends I personally did not go the CCNP route My company did not recognize it, so it was not worth pursuing for me If your company will give you a raise or if you prefer a methodical progression, then perhaps CCNP is something you should consider I know that if you work for a Cisco partner, they will love for you to get a CCDP, which requires the CCNP, first, but don't feel that you must go this route Please note that my recommended lab preparation blueprint assumes that you have already passed the written exam and have subsequently scheduled your lab exam, since the backlog is approaching something like six months This works to your advantage because you are going to need a good six months of preparation time If you are going to embark on this quest, then you need
to be realistically prepared to put in 300-500 hours of preparation time Your preparation needs to start by examining Cisco's official CCIE web site
The Cisco Web Site
One of the best sources of information about the lab exam is Cisco's web site itself If you examine the CCIE section, you will find a wealth of beneficial information For example, if you examine the latest news, you will find that certain topics have been removed from the lab exam including LAT, DECnet, Apollo, Banyan VINES, ISO CLNS, XNS, ATM LANE, X.25, and AppleTalk You can also find out that any IOS feature through IOS version 12.0 may be included in the exam You will also see that there is an equipment list, for which you are responsible:
• 2500 series routers
• 2600 series routers
• 3600 series routers
• 4000 and 4500 series routers
• 3900 series Token Ring switches
• Catalyst 5000 series switches
Why is this important? Have you ever configured a 3900 series Token Ring switch? If you haven't, you better find a
Trang 3way to learn Trying to do something for the first time during the lab is not a good idea Ideally, you should have seen every feature at least once prior to the lab Here are some additional examples: do you know what the differences are
in password recovery procedures for the various routers and switches? Again, the lab is not the place to learn them
The Cisco web site also includes other important topics such as how to book the exam, where the exams are held, and how much the exam costs You should frequently check the appropriate web sites because this is, after all, the official source of information
Exam Description
A lot of people wonder just what the exam is like since the strict NDA keeps you from learning much about the exam until you experience it yourself This same NDA prevents me from sharing much, but you can get some idea of what the exam is like from the official web pages and from the 2001 CCIE Power Sessions at Networkers
Networkers is Cisco's annual user conference held several times a year throughout the world At networkers, you can receive detailed technical information about virtually any Cisco product or technology at levels ranging from the most basic to advanced beyond the CCIE level
At Networkers, Mike Reid talked about the general makeup of the exam The lab consists of a two-day practical exam with the first day being devoted to building a network to meet a set of specifications After the first day is completed, the proctor grades the exam and reviews the results with the candidate The exact time of the review varies
depending upon the location of the exam The review could be the evening of the first day or the morning of the second day Day two begins by having the candidate build upon the first day's network until a break is taken at
lunchtime The proctor will again grade this work over lunch and review the results with the candidate Finally, the candidate will troubleshoot a network in the afternoon At each major break, the candidate must obtain enough points
to pass on to the next section If the candidate does not score enough points, then the lab is over at that point The lab exam is particularly difficult because the candidate needs to score 80% in order to pass the exam
The network specification is presented as a series of questions
These questions can be completed in any order, but some later
parts may depend upon successful completion of earlier parts The
point values for each question are shown on the exam paper If you
view the presentations from the Networkers CCIE Power Session,
you will see a sample topology and question It is worth noting that
there are no partial marks given Each question is either 100%
correct or 100% wrong to standardize grading around the world
You should also be aware that some questions can be solved
numerous ways, all of which are equally correct As long as your
solution meets the requirements of the question, you should get
credit for it You should also be aware of the lab rules so that you
can incorporate them into your practice and study sessions For
example, during a recent Networkers CCIE Power Session, one of
the rules presented is that, unless a question explicitly states that you can, you may not use any static routes or
default routes You need to be emotionally ready for restrictions such as this, which don't reflect the real world but are what you need to do to pass Cisco's lab One very distinguished consultant failed the lab because she immediately
began to argue with the proctor that some scenarios were unrealistic, and lost valuable time The scenarios were
unrealistic So?
A review of the groupstudy.com archives for the CCIE lab mailing list shows that a lot of people wonder about the physical makeup of the lab According to the above Networkers CCIE Lab Power Session, each candidate has his/her own PC and rack of equipment Physical connections may be made using RJ-45 and serial patch panels at the front
of the rack Since you already have a list of the possible equipment in each rack, you must be prepared to work with each different type of equipment You will probably find that the exact equipment you will have in your rack during the exam depends on where you are taking the exam and which rack you have I would not get too wrapped up in
worrying about the exact rack equipment list If you have any questions about particular equipment, you can ask the proctors before or during the exam or you can ask the people at Cisco who schedule the exam
For example, I called Cisco and asked if they could tell me if I would need to know how to configure the 3920 Token Ring switch or if they would just have old-fashioned MAUs At that time, a representative of the CCIE program told me that, although they would have 3920 Token Ring switches present; they would only be used as MAUs Please be
aware that this was over a year ago You must check for yourself at your particular lab Another example of how you
can get help is to ask the proctor how to use an RJ45 or serial patch panel If you have ISDN present on your lab exam, you might want to ask the proctor what the ISDN switch type is or similar questions Now that you have a basic understanding of what the lab exam is like within the bounds of the NDA, there are a number of further actions that I recommend you take to prepare for the exam
Further Recommendations
Lab Tip: An excellent tip to take with you into
the lab is that although the rules say you may not use any static routes, if you are having difficulty solving a particular problem, and later questions depend on solving that problem, go ahead and put in the static routes Sure, you will lose points for doing it, but you may save more points by being able to make the rest of your lab problems work You can always go back later and remove the static route to fix things the correct way if you can figure that way out
Trang 4I highly recommend that you join the CCIE mailing list at www.groupstudy.com as well as the general Cisco
Professional mailing list at the same site By joining the mailing lists, you will become part of a community of other people striving for the same goal, and you will learn from them by reading the day-to-day messages The lists provide
an important benefit by letting you interact with a group of mentors who have already passed the exam You may have difficulty in finding a CCIE mentor for in-person help, but you can find any number of virtual mentors on the mailing lists The daily messages are also an excellent indicator of your own readiness for the lab exam When you can answer most of the problems other candidates are presenting in their messages without resorting to books, documentation, etc., then you know you are close to being ready for the lab exam
One of the greatest challenges you will face in preparing for the lab exam is building your hands-on experience by developing or finding difficult, quality practice scenarios You can find some excellent free labs at www.fatkid.com While I used these labs, I also paid for and highly recommend purchasing Mark Russell's labs at
www.ccbootcamp.com I know that, at $650 per set, they are expensive, but they are definitely worth it I highly
recommend that you make up some of your own scenarios to test every feature of IOS for a given topic For example,
I would take the documentation CD, look at the IOS routing protocols section, and choose a topic such as OSPF I would then practice every possible OSPF command so that I at least know what each command does This method works particularly well for the Catalyst 5000 switch Since the Catalyst 5000 is not nearly as complex as a router, I studied for the exam by going through the Catalyst 5000 documentation and practicing with every feature until I felt comfortable with each feature Do you know how to configure a dynamic VLAN? Do you know how to make sure a given switch is the root of the spanning tree? These are a few examples of the topics you can learn by reviewing the documentation
Find a Mentor
There is no substitute for finding a skilled mentor and/or study partner to help you focus your study efforts No CCIE should ever tell you the exact makeup of the exam because that would be a violation of the NDA, but what a CCIE can do is help you focus your studies For example, if I were mentoring someone and checked on a practice lab they were doing, I might say something like, "you did an excellent job getting basic frame connectivity using point-to-point sub-interfaces, but why don't you try it again using a multipoint sub-interface and again using physical interfaces." A mentor is also very helpful when you just do not understand a given topic For example, suppose that you are weak at BGP A mentor is going to be able to point you to additional study material as well as challenge you with a
progressive series of problems so that you learn BGP well by the time you take the lab exam
Develop Confidence and Self-Control
You can know every IOS command, know every CatOS command and understand every possible protocol, yet fail the exam because you mismanaged either your stress level or your time This exam is not just about being able to
configure the equipment to specifications It is about being able to configure the equipment to specifications, without error, in a highly compressed time frame My friend Bruce Caslow said it best, "I can pass any test if I have enough time, and I can make a few phone calls." Unfortunately, the CCIE exam is not "Who Wants To Be A Millionaire." You don't have any lifelines, and you can't phone a friend All you have are your own wits, your ability to remain calm and concentrate, and the official Cisco documentation in both printed form and CD form So, you need to work on time management and stress management We'll take a detailed look at time management first
Time Management
I used a number of techniques for time management These techniques were developed both from reading
recommendations on the groupstudy.com CCIE lab mailing list and in Mentor Technologies' ECP1 class There is nothing magical about these techniques, they are just good common sense
Improving Your Speed
One of the great challenges of the CCIE lab is managing your time well It is critical that you finish soon enough to have an hour or more at the end of Day One and a half-hour or more after the morning of Day Two to check your work There are a number of techniques you can use to speed up your work, but here are the ones that I use:
1 Practice typing until you can type (accurately) fairly fast The commands should be second nature to you
2 Learn to use aliases Practice frequently with the ones you like I will include a few below
3 Master the Documentation CD Know where to find every topic listed in Bruce Caslow's book You simply do not have the time to search the CD for the topic during the exam If you are constantly in the CD during the exam, then you are not ready for it yet You should only need to use the CD to check syntax, look up an
obscure command, check your work, or similar brief uses
Trang 54 Learn not to spend too much time on something you do not know Get the points for the things that you know cold first, then come back and finish the things that you do not know later, if you can
5 When you first start, use a base configuration and paste it into every router Be sure to check that everything
is there on every router Don't be fancy and try to name your routers things like parsley, sneezy, etc Stick to r1, r2, r3, etc Here is the base configuration I used for all of my practice scenarios:
Base Configuration
ip tcp syn-wait 5
no ip domain-lookup
ip subnet-zero
ip classless
alias exec c conf t
alias exec br sho ip int brief
alias exec i sho ip ro
alias exec b sho ip bgp
alias exec bs show ip bgp summ
alias exec st show isdn status
line vty 0 4
no exec-timeout
no login
privilege level 15
password cisco
line con 0
no exec-timeout
no login
password cisco
line aux 0
no exec-timeout
no login
password cisco
Watch the spaces when you paste in the configurations You wouldn't want to have to waste time doing a password recovery because you had an unknown number of spaces after the password "cisco." I also draw a nice neat network diagram before I practice any scenario or work on any customer network
6 Know the IOS shortcut commands Be able to use keyboard shortcuts such as control+A to move your cursor
to the beginning of the line, control+E, to move your cursor to the end of the line, and control+R to repaint the present line You can also use control+shift+6 to cancel a command such as a ping or traceroute
Although you need to be prepared to use the newer style commands such as copy run start, I prefer to use the older style commands such as wr for write to save the current running config to NVRAM instead of the lengthier copy run start command I also use wr t for write terminal instead of show run Does this make a difference? It will certainly improve your speed if you only have to type wr instead of copy run start 500 times
in a day, but there is a caveat Cisco has been warning for years that they are going to remove the old style commands from IOS, so make sure you are prepared to use both If I know that I just saved a config, then I
would use the sh config instead of sh run or wr t because it shows the last saved running config and is faster
to display than using sh run since sh run spends some time computing the current running config It doesn't
make too much difference with a fast router like a 3640, but it sure does with a slow router like a 2500 Finally,
I use un all to turn off debugging instead of the alternatives of turning off each debug command or typing in the lengthier undebug all command.
The Network Diagram
When working on any routing and switching scenario, you should draw a neat network diagram with clear labeling for each router, interface type and number, network and node addresses, routing protocols, area assignments, etc I have read on groupstudy.com that some people find it helpful to use colored pencils for each different protocol such
as black for IP, green for IPX, etc I never did this myself I am just careful not to draw a diagram that is too small I would like to caution you against spending too much time drawing a perfect diagram Time is precious in the lab Don't waste your valuable time using templates to draw perfect circles, etc Just hand draw neatly with lots of room for adding detail Since a network drawing only takes up one side of a piece of paper, I learned some very valuable tips for both the CCIE lab and work in general from Bruce Caslow On the reverse side of the drawing, I make a chart listing each router by hostname, by model, what IOS image it is running, and how much current DRAM and Flash the router has I do the same for the switches This information might be very valuable during troubleshooting whether in the lab or in real life
Network Address Planning
Trang 6Address planning is a very important topic I cannot emphasize enough that you need to read your entire test paper twice, all the way through, before you ever configure any equipment or even plan anything Suppose you did not do this and only read one section of the exam and decided to use 10.0.1.0/24 to complete the current section You would hate life down the road if you needed to use that same address block somewhere else I use several techniques whenever I am planning IP addresses Unfortunately, I can't remember where I learned them so I can't give proper credit Here is my first technique By the way, I do this whether I am in the lab or working at a client site or on my own practice scenarios I take an 8.5 X 11 sheet of paper (or A4 in Europe), and draw a line from one side of the paper to the other I then put arrows on each end and label this line for every classful address block, but particularly /16s I then use this line to mark where I am using major subnets Here is an example Suppose that I am planning to use the 172.16.0.0/16 address space to subnet for a lab scenario I will make the first entry as in Figure 2
Figure 2.
I will then mark off each chunk of address space I use so that I know what is remaining Suppose I wanted to use 172.16.1.0/24, 172.16.2.0/24, and 172.16.3.0/24 for loopbacks and 172.16.16.0/20 for network addressing My
diagram would then appear as in Figure 3
Figure 3.
By using this type of method, I have a clear graphical representation of address space already used and address space still available for future use I also employ another method to keep track of my address space used, by router and interface What I do is make a simple table by router name with each interface filled in Under each interface, I list the IP address as well as the addresses for any other protocols Here is an example Suppose I had the network depicted below
Figure 4.
I would construct a table for this network by filling in addresses as I go, but also noting when an interface is unused or nonexistent for a given router I can also use this table to check that my addresses are entered correctly on each
router by using show ip route connected as well as to check basic IP connectivity In most cases, I will know my IP
configuration is correct when I can ping every address from every router
Trang 7Preparing for the Lab Exam
This section will give you tips on just how you should go about preparing for the lab exam These tips are a result of
my own preparation experiences as well as those of numerous other members of groupstudy.com Let's begin by taking a detailed look at the books that I suggest for your library Yes, there are many more books out there; these are the ones I recommend and use on a daily basis
Books to Read
Do you have to read every page of every book? No, but you do need to read certain key sections Obviously, if a book has sections about topics that are no longer on the exam, then you do not need to read those sections Here are the books that I feel you must read and absorb:
CCIE Certification Bridges, Routers, and Switches for CCIEs - Bruce Caslow (Don't walk, RUN and get it,
memorize it! Be sure to get the Second Edition.)
Internet Routing Architectures - Sam Halabi (The BGP material in this book is essential and difficult to find
elsewhere Be sure to get the Second Edition.)
CCIE Professional Development Routing TCP/IP Volume I - Jeff Doyle (The best book for the routing protocols.) CCIE Professional Development LAN Switching - Kennedy Clark (The best book on the Catalyst.)
All-In-One CCIE Lab Study Guide - Stephen Hutnik & Michael Satterlee (Although this book is not a true all-in-one
guide, it does present some topics well, such as NTP, HSRP, and configuring a router as a TFTP server It provides a good basic start for lab work.)
Developing IP Multicast Networks: The Definitive Guide to Designing and Deploying CISCO IP Multi-cast Networks - Beau Williamson (Although this book may be overkill, it is excellent.)
Cisco Multicasting Routing & Switching - William Parkhurst (This is the multicast book I used Beau's book was
not available yet.)
Cisco Routing Illustrated: A Workbook for CCIEs and CCNPs - Bruce Caslow (Keep an eye out for this book It
should be an excellent source for lab scenarios.)
Now that we have sufficient reading material, let's look at the next important ingredient: a home lab
Obtaining a Home Lab
You cannot hope to pass the CCIE lab without mastering IOS, and this is only possible if you have extensive
hands-on router and switch time The best way to get this experience and I believe this is an absolute requirement is to assemble your own lab You can assemble a lab at home or at work several ways, but you must have access to a quality lab Your home lab doesn't need to have every piece of equipment on the published equipment list, but more
is definitely better I would strive to obtain 6-8 routers with a Catalyst 5000 and ISDN simulator I think you can obtain enough experience with ATM and voice in the ECP-1 class I am going to recommend or by renting a remote rack with this equipment
All of your routers, except for maybe the frame switch, should have at least 11.2 Enterprise Plus You should probably have 12.0, since the official web site says you need to be prepared for IOS through 12.0 This may require you to upgrade the DRAM and Flash on the routers you acquire Make sure that one of your routers has at least four serial ports to act as a frame switch Don't worry too much about obtaining Token Ring gear If you have IOS version 11.3 or better, you can use virtual token-ring interfaces, which simulate the real thing Preparing for the CCIE lab may sound like an expensive endeavor and it is but you can get away with buying used equipment on ebay.com and resell it
Router Serial 0 Serial 1 Ethernet 0 Token Ring 0 BRI 0 Loopback 0
R1 2503 172.16.32.1/30 172.16.16.1/20 Unused N/A 172.16.32.5/30 172.16.1.1/24 R2 2504 172.16.16.2/20 Unused N/A 172.16.80.1/24 172.16.32.6/30 172.16.2.2/24
Trang 8later; or borrow it from work or perhaps even from your friendly Cisco rep It would cost you about $10,000 to acquire the equipment you need to practice for the lab so you may consider sharing the cost with a few friends
Here are my two recommendations for lab equipment The first lab is the bare bones "get the most lab for your buck." The second lab is the no-expense-spared, totally complete lab
Lab 1 - The Budget Lab
Cisco 2521/2522 - Use as a frame switch
Cisco 2509/2511 - Use as a terminal server
Cisco 2513 has 1 Token Ring / 1 Ethernet / 2 Serial Ports
Cisco 2514 has 2 Ethernet / 2 Serial Ports
Cisco 2503(2) has 1 Ethernet / 1 ISDN BRI / 2 Serial Ports
Cisco 2504 has 1 Token Ring / 2 ISDN BRI / Serial Ports
ISDN Simulator
Catalyst 2901 / 5002 / 5005 with a Supervisor 1 module and an Ethernet blade
Lab 2 - The Complete Lab
Cisco 2521/2522 - Use as a frame switch
Cisco 2509/2511 - Use as a terminal server
ISDN Simulator
Catalyst 2901 / 5002 / 5005 with a Supervisor 1 module and an Ethernet blade
LightStream 1010 ATM Switch with 4 X OC3 MM interfaces
Cisco 2503(2) has 1 Ethernet / 1 ISDN BRI / 2 Serial Ports
Cisco 2504 has 1 Token Ring / 2 ISDN BRI / Serial Ports
Cisco 4500 with ATM OC-3 MM Module, Ethernet Module, and Serial Port Module
Cisco 3640 with ATM OC-3 MM Module, FXS Voice, FE Module
Cisco 2600/ Cisco 3620 with FXS Voice, Serial Module
Two analog phones
Catalyst 3920 Token Ring Switch
Now that you know what books to buy and what equipment to use to build your lab, you should take a look at your training requirements Do you need to take any classes? It depends on your individual skills, but I highly recommend taking at least one class
Training Classes
One of the questions that I see frequently is about which class to take, especially which boot camp to take I cannot comment on every boot camp out there because I have only taken one class I highly recommend Mentor
Technologies' ECP1 class
Trang 9You can count on five twelve-hour days covering Bruce Caslow's CCIE Certification Bridges, Routers, and Switches for CCIEs book combined with extensive hands-on lab exercises The class is often taught by Bruce, but is also
taught by Val Pavlichenko and Fred Ingham All three are outstanding instructors I am certain that you will not be disappointed with this class It is important to know that ECP1 is not meant to be a boot camp, rather, ECP1 is meant
to be a strong refresher class to let you know just where you stand in your preparation so that you can assess your strong points and weak points It is most definitely not a brain dump of the lab exam It is a very valuable chance to spend something like 60 hours in one week eating, breathing, and living high-level internetworking with a master instructor
Do you need to take all the recommended classes as listed on the CCIE web site or the sites of Cisco's training partners? No, you don't Sure, some classes can be helpful, but you do not have to take them I personally took the ACRC and ECP1 classes One class that I think would be helpful is the CVOICE class, but I don't think it is an
absolute necessity
I would like to offer some tips for any course of this nature to maximize your learning experience
1 Come prepared If you do not understand most of the material in "Bridges, Routers, and Switches," then you are not ready for the class, so reschedule
2 Bring your laptop with you, and save all your sessions to log files This way you can go back later and review the setups with which you are not familiar, such as ATM or Voice over IP
3 Stay the entire time This time is precious, so don't leave at 6:00 pm just to go watch TV
4 Network with your classmates You can learn valuable techniques and get ideas for areas in which you need
to improve
5 Be sure you come away from the class with a clear picture of where you are strong and where you are weak Work hard on the weak points, not the strong points Concentrate on the material with which you are
uncomfortable
6 When you finish the class, go home and rework all the labs until you understand them thoroughly
7 Take the class 4-6 weeks before the lab so that you have enough time to practice what you learn in the class
8 Remember the debugging techniques you will learn in the class Learn how to prove to yourself that every configuration is correct by using the appropriate debug or show commands
Skills Needed for the CCIE Lab
Although there are many direct skills you need to learn for the CCIE lab exam, there are some indirect skills as well Some of the indirect skills you need to learn are how to configure a router to act as a frame-relay switch and how to configure a terminal server You may want to know how to configure an ATM switch to practice with
How to Configure a Router as a Frame Switch
One of the skills that you need to learn for the CCIE lab is how to configure a router as a frame-relay switch It isn't so much that you need to be able to configure a router as a frame-relay switch for the lab itself (although if a given configuration is in IOS, it is still fair game) Rather, it is the fact that you need to be able to configure a router as a frame-relay switch to practice your own scenarios since you will want to study frame-relay heavily The commands you need to configure a router as a frame switch are relatively simple In this example, we are assuming that you have a router with at least four serial ports, although you could easily have more, e.g a 2522 has 10 serial ports Here is a step-by-step example:
You need to use the global command frame-relay switching to enable frame-relay switching This is the only global
command you need All the rest are interface commands
The next command you need to enter is an interface command to define the frame-relay interface type as a DCE Remember that, in general, the DCE side of the circuit is on the telco side, and the DTE side is on the Customer Premises Equipment (CPE) side The next command defines the routing between the DLCIs, so it is very important
that you understand the syntax of the frame-relay route command Here is a practical example:
Frame-switch#config t
Trang 10Frame-switch(config)#frame-relay switching
Frame-switch(config)#interface s 0
Frame-switch(config-if)#encapsulation frame-relay ietf
Frame-switch(config-if)#frame-relay intf-type dce
Frame-switch(config-if)#frame-relay route 102 interface serial1 201
Frame-switch(config-if)#frame-relay lmi-type q933a
Note that the encapsulation frame-relay command actually specifies which of the two frame-relay encapsulation
types the circuit will use: cisco (the default), or ietf (the standard for connecting to other manufacturer's equipment) You can also set which of the three lmi-types you want to use here: cisco (the default), CCITT (q933a), or ANSI
Finally, look at the syntax of the frame-relay route command itself This is where you set the DLCI for each interface
The example above is saying that all data from interface s 0 will use DLCI 102 to reach interface s 1 using DLCI 201
It should be obvious that interface s 1 needs a similar configuration Here is what it looks like:
Frame-switch(config)#interface s 1
Frame-switch(config-if)#encapsulation frame-relay ietf
Frame-switch(config-if)#frame-relay intf-type dce
Frame-switch(config-if)#frame-relay route 201 interface serial0 102
Frame-switch(config-if)#frame-relay lmi-type q933a
From your reading, you should be aware that significant differences exist between a fully meshed network and a partially meshed network For frame-relay, a partial mesh presents many difficulties It is imperative that you
understand the differences between the two types of meshed networks
More detailed information about Frame Relay can be found in the CertificationZone Frame Relay Study Guide
Fully Meshed Frame Switch
Figure 5 A Fully Meshed Frame-relay Network
In this simple example of a fully meshed network of three routers, notice how each interface has two frame-relay route statements associated with it You should see that each frame-relay route statement has a complement under its paired interface
Frame-switch#show run
Building configuration
Current configuration:
!
version 11.3
!
hostname Frame-switch
!
frame-relay switching
!
interface Serial0
no ip address
encapsulation frame-relay