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Assessment testing to focus and direct your studies
In-depth coverage of official exam objectives
Hundreds of challenging practice questions, in the book and on the CD
Sample simulation questions
Authoritative coverage of all exam topics, including:
Planning the campus network
Connecting the switch block
Designing and implementing VLAN technologies
Understanding Layer 2 switching
Working with Spanning Tree Protocol (STP)
Using Spanning Tree with VLANs
Setting up inter-VLAN routing
Using Multi-Layer Switching (MLS)
Understanding multicast capabilities
Featured on the CD
The enclosed CD is packed with vital preparation tools and materials, beginning with the Sybex EdgeTest testing engine for Cisco's new Switching exam, 640-604. Loaded with hundreds of practice questions, including sample simulation questions, it lets you test yourself chapter by chapter. You'll also find electronic flashcards for your PCs, Pocket PCs, and Palm handhelds, along with two practice exams that will help you prepare for the test. A fully searchable electronic copy of the book is also included.
About the Author
Todd Lammle, CCNP, has more than 20 years of experience working with various LAN and WANs, and has been working on Cisco router networks since 1986. He is CEO and Chief Scientist of RouterSim, LLC, and President of GlobalNet Training, Inc. Eric Quinn, CCSI, CSS1, CCNP + Voice is an Arizona-based instructor and security consultant.
The main challenge for network administrators is to make the campus network run efficiently and effectively. To do this, they must understand current campus networks as well as the new emerging campus networks. Therefore, in this chapter, you will learn about current and future requirements of campus internetworks. We'll explain the limitations of traditional campus networks as well as the benefits of the emerging campus designs. You will learn how to choose from among the new generation of Cisco switches to maximize the performance of your networks. Understanding how to design for the emerging campus networks is not only critical to your success on the Switching exam, it's also critical for implementing production networks.
As part of the instruction in network design, we'll discuss the specifics of technologies, including how to implement Ethernet and the differences between layer 2, layer 3, and layer 4 switching technologies. In particular, you will learn how to implement FastEthernet, Gigabit Ethernet, Fast EtherChannel, and Multi-Layer Switching (MLS) in the emerging campus designs. This will help you learn how to design, implement, and maintain an efficient and effective internetwork.
Finally, you will learn about the Cisco hierarchical model, which is covered in all the Cisco courses. In particular, you will learn which catalyst switches can-and should-be implemented at each layer of the Cisco model. And you will learn how to design networks based on switch and core blocks.
This chapter, then, will provide you with a thorough overview of campus network design (past, present, and future) and teach you how, as a network administrator, to choose the most appropriate technology for a particular network's needs. This will allow you to configure and design your network now, with the future in mind.
It doesn't seem that terribly long ago that the mainframe ruled the world and the PC was just used to placate some users. However, in their arrogance, mainframe administrators never really took the PC seriously, and like rock 'n' roll naysayers, they said it would never last. Maybe they were right after all-at least in a way. In the last year or two, server farms have replaced distributed servers in the field.
In the last 15 years we have seen operators and managers of the mainframe either looking for other work or taking huge pay cuts. Their elitism exacerbated the slap in the face when people with no previous computer experience were suddenly making twice their salary after passing a few key certification exams.
Mainframes were not necessarily discarded, they just became huge storage areas for data and databases. The NetWare and NT server took over as a file/print server and soon started running most other programs and applications as well.
The last 20 years have witnessed the birth of the LAN and the growth of WANs and the Internet. So where are networks headed in the twenty-first century? Are we still going to see file and print servers at all branch locations? Are all workstations just going to connect to the Internet with ISPs to separate the data, voice, and other multimedia applications?
In the 1990s, the traditional campus network started as one LAN and grew and grew until segmentation needed to take place just to keep the network up and running. In this era of rapid expansion, response time was secondary to just making sure the network was functioning.
And by looking at the technology, you can see why keeping the network running was such a challenge. Typical campus networks ran on 10BaseT or 10Base2 (thinnet). As a result, the network was one large collision domainnot to mention even one large broadcast domain. Despite these limitations, Ethernet was used because it was scalable, effective, and somewhat inexpensive compared to other options. ARCnet was used in some networks, but Ethernet and ARCnet are not compatible, and the networks became two separate entities. ARCnet soon became history.
Because a campus network can easily span many buildings, bridges were used to connect the buildings together; this broke up the collision domains, but the network was still one large broadcast domain. More and more users were attached to the hubs used in the network, and soon the performance of the network was considered extremely slow.
Performance Problems and Solutions
Availability and performance are the major problems with traditional campus networks. Bandwidth helps compound these problems. The three performance problems in traditional campus networks included collisions, broadcasts and multicasts, and bandwidth.
A campus network typically started as one large collision domain, so all devices could see and also collide with each other. If a host had to broadcast, then all other devices had to listen, even though they themselves were trying to transmit. And if a device were to jabber (malfunction), it could almost bring the entire network down.
Because routers didn't really become cost effective until the late 1980s, bridges were used to break up collision domains, but the network was still one large broadcast domain and the broadcast problems still existed. However, bridges did break up the collision domain, and that was an improvement. Bridges also solved distance-limitation problems because they usually had repeater functions built into the electronics and/or they could break up the physical segment.
The bandwidth of a segment is measured by the amount of data that can be transmitted at any given time. Think of bandwidth as a water hose; the amount of water that can go through the hose depends on different elements:
The pressure is the current and the bandwidth is the size of the hose. If you have a hose that is only 1/4 inch in diameter, you won't get much water through it regardless of the current or the size of the pump on the transmitting end.
Another issue is distance. The longer the hose, the more the water pressure drops. You can put a repeater in the middle of the hose and reamplify the pressure of the line, which would help, but you need to understand that all lines (and hoses) have degradation of the signal, which means that the pressure drops off the farther the signal goes down the line. For the remote end to understand digital signaling, the pressure must stay at a minimum value. If it drops below this minimum value, the remote end will not be able to receive the data. In other words, the far end of the hose would just drip water instead of flow. You can't water your crops with drips of water; you need a constant water flow.
The solution to bandwidth issues is maintaining your distance limitations and designing your network with proper segmentation of switches and routers. Congestion on a segment happens when too many devices are trying to use the same bandwidth. By properly segmenting the network, you can eliminate some of the bandwidth issues. You never will have enough bandwidth for your users; you'll just have to accept that fact. However, you can always make it better...
|Ch. 1||The Campus Network||1|
|Ch. 2||Connecting the Switch Block||49|
|Ch. 4||Layer 2 Switching and the Spanning Tree Protocol (STP)||149|
|Ch. 5||Using Spanning Tree with VLANs||181|
|Ch. 6||Inter-VLAN Routing||227|
|Ch. 7||Multi-Layer Switching (MLS)||263|
|Ch. 9||Configuring Multicast||353|
|App. A: Commands Used in This Book||389|
|App. B: Internet Multicast Addresses||397|
Posted May 2, 2001
The books starts very strong for switching. Chapters 1-5 are very detailed and explained. However, the chapters that pertains to MLS snd multicast are not clear at all. The examples and labs are incomplete and will leave you very confused. The questions at the end of the chapters were not very helpful for the exam. The exam questions were much more complicated.I passed the exam with a very good score. I used additional materials such as Exam Cram, which is very good.Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted November 26, 2000
The wording of the book is very simple to understand. The CD that comes with the book is excellent for command practice. Books from CiscoPress, and Syngress Osborne (McGrawHill) are also good, but what separates them is the CD that comes with this book.Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted November 26, 2000
This is a best book to understnad the Cisco Switching concept and also to pass swiching exam.Authour has explained everything very nicely.questions and preparation test are very helpful.Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.