Ordering WAN Technology and Contracts

When you order WAN transport technology, early planning is key. It usually takes at least 60 days for the carrier to provision circuits. Generally, the higher a circuit's capacity, the more lead time is required to provision. When ordering bandwidth overseas, a lead time of 120 days is fairly common. WAN transport in most cases includes an access circuit charge and, at times, distance-based charges. However, some carriers have eliminated TDM distance-based charges because T1s are readily...

Cisco UWN Architecture

With the explosion of wireless solutions in and out of the enterprise, designers must create solutions that provide mobility and business services while maintaining network security. The Cisco Unified Wireless Network (UWN) architecture combines elements of wireless and wired networks to deliver scalable, manageable, and secure WLANs. As shown in Figure 4-2, the Cisco UWN architecture is composed of five network elements Client devices These include laptops, workstations, IP phones, PDAs, and...

WLAN Security

WLANs provide an effective solution for hard-to-reach locations and enable mobility to a level that was previously unattainable. However, WLANs without any encryption present a security risk, because publicly available software can obtain the SSIDs. The productivity improvements with WLANs are just beginning, however. The Wired Equivalent Privacy (WEP) security protocol, used in the IEEE 802.11b standard, is considered faulty and vulnerable to numerous attacks. The 802.11b protocol is the most...

Wireless LAN Standards

Wireless LAN (WLAN) applications include inside-building access, LAN extension, outside building-to-building communications, public access, and small office home office (SOHO) communications. The first standard for wireless LANs is IEEE 802.11, approved by the IEEE in 1997. The current specification is IEEE 802.11-1999, with many amendments thereafter. IEEE 802.11 implemented wireless LANs at speeds of 1 Mbps and 2 Mbps using Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread...

Do I Know This Already

Health Insurance Portability and Accountability Act (HIPAA) applies to the protection of private health information that is used electronically. 2. B. Reconnaissance techniques are used to gather information from hosts attached to the network. 3. A. Denial of service (DoS) attacks aim to overwhelm resources such as memory, CPU, and bandwidth, thus impacting the target system and denying legitimate users access. 4. D. Rate limiting can control the rate of bandwidth that is used for...

Foundation Summary

The Foundation Summary section of each chapter lists the most important facts from the chapter. Although this section does not list every fact from the chapter that will be on the CCDA exam, a well-prepared CCDA candidate should at a minimum know all the details in each Foundation Summary before taking the exam. This chapter covered the following topics that you need to master for the CCDA exam Traditional voice architectures The architecture of TDM voice networks. You must understand PSTN...

Do I Know This Already Quiz

The purpose of the Do I Know This Already quiz is to help you decide whether you need to read the entire chapter. If you intend to read the entire chapter, you do not necessarily need to answer these questions now. The eight-question quiz, derived from the major sections in the Foundation Topics portion of the chapter, helps you determine how to spend your limited study time. Table 9-l outlines the major topics discussed in this chapter and the Do I Know This Already quiz questions that...

Pv4 Address Classes

IPv4 addresses have five classes A, B, C, D, and E. In classful addressing, the most significant bits of the first byte determine the address class of the IP address. Table 7-8 shows the high-order bits of each IP address class. Table 7-8 High-Order Bits of IPv4 Address Classes Table 7-8 High-Order Bits of IPv4 Address Classes *x can be either 1 or 0, regardless of the address class. *x can be either 1 or 0, regardless of the address class. Again, the IPv4 Class A, B, and C addresses are...

Border Gateway Protocol Route Manipulation and IP Multicast 387

Do I Know This Already Quiz 387 Foundation Topics 390 BGP 390 BGP Neighbors 391 eBGP 392 iBGP 392 Route Reflectors 393 Confederations 395 BGP Administrative Distance 396 BGP Attributes, Weight, and the BGP Decision Process 396 BGP Path Attributes 396 Next-Hop Attribute 397 Local Preference Attribute 397 Origin Attribute 398 AS Path Attribute 398 MED Attribute 398 Community Attribute 399 Atomic Aggregate and Aggregator Attributes 399 Weight 400 BGP Decision Process 401 BGP Summary 402 Route...

Gigabit Ethernet 10GE Design Rules

The IEEE 802.3ae supplement to the 802.3 standard, published in August 2002, specifies the standard for 10 Gigabit Ethernet. It is defined only for full-duplex operation over optical media. Hubs or repeaters cannot be used because they operate in half-duplex mode. It allows the use of Ethernet frames over distances typically encountered in metropolitan-area networks (MAN) and WANs. Other uses include data centers, corporate backbones, and server farms. 10GE has seven physical media...

LAN Design Types and Models

LANs can be classified as large-building LANs, campus LANs, or small and remote LANs. The large-building LAN typically contains a major data center with high-speed access and floor communications closets the large-building LAN is usually the headquarters in larger companies. Campus LANs provide connectivity between buildings on a campus. Redundancy is usually a requirement in large-building and campus LAN deployments. Small and remote LANs provide connectivity to remote offices with a...

Converting Decimal to Binary Numbers

This procedure is similar to converting from hex to decimal (by dividing), but now you divide the decimal number by 2. You use each residual to build the binary number by prepending each residual bit to the previous bit, starting on the right. Repeat the procedure until you cannot divide anymore. The only problem is that for large numbers, you might have to divide many times. You can reduce the number of divisions by first converting the decimal value to a hexadecimal value and then converting...

Qa

As mentioned in the Introduction, you have two choices for review questions here in the book or the exam questions on the CD-ROM. The answers to these questions appear in Appendix A. For more practice with exam format questions, use the exam engine on the CD-ROM. 1. What type of WAN technology provides a dedicated connection from the service provider a. Circuit-switched data connection 2. What type of topology suffers from a single point of failure 3. What kind of topology requires that each...

Pv6 Address Allocations

The leading bits of an IPv6 address can define the IPv6 address type or other reservations. These leading bits are of variable length and are called the format prefix (FP). Table 8-2 shows the allocation of address prefixes. The IPv6 address space was delegated to IANA. You can find current IPv6 allocations at Many prefixes are still unassigned. Unspecified, loopback, IPv4-compatible Reserved for Internetwork Packet Exchange (IPX) allocation Reserved for geographic-based unicast addresses...

Ethernet Design Rules

Ethernet is the underlying basis for the technologies most widely used in LANs. In the 1980s and early 1990s, most networks used 10-Mbps Ethernet, defined initially by Digital, Intel, and Xerox (DIX Ethernet Version II) and later by the IEEE 802.3 working group. The IEEE 802.3-2002 standard contains physical specifications for Ethernet technologies through 10 Gbps. Table 3-2 describes the physical Ethernet specifications up to 100 Mbps. It provides scalability information that you can use when...

IP Address Subnet Design Example

This example shows subnetting for a small company. Say the company has 200 hosts and is assigned the Class C network of 195.10.1.0 24. The 200 hosts are in six different LANs. You can subnet the Class C network using a mask of 255.255.255.224. Looking at the mask in binary (11111111 11111111 11111111 11100000), the first three bytes are the network part, the first 3 bits of the fourth byte determine the subnets, and the five remaining 0 bits are for host addressing. Table 7-13 shows the...

BGP Attributes Weight and the BGP Decision Process

BGP is a protocol that uses route attributes to select the best path to a destination. This subsection describes BGP attributes, the use of weight to influence path selection, and the BGP decision process. BGP uses several attributes for the path-selection process. BGP uses path attributes to communicate routing policies. BGP path attributes include next hop, local preference, AS path, origin, multiexit discriminator (MED), atomic aggregate, and aggregator. Of these, the AS path is one of the...

Gigabit Ethernet Design Rules

Gigabit Ethernet was first specified by two standards IEEE 802.3z-1998 and 802.3ab-1999. The IEEE 802.3z standard specifies the operation of Gigabit Ethernet over fiber and coaxial cable and introduces the Gigabit Media-Independent Interface (GMII). These standards are superseded by the latest revision of all the 802.3 standards included in IEEE 802.3-2002. The IEEE 802.3ab standard specified the operation of Gigabit Ethernet over CAT 5 UTP. Gigabit Ethernet still retains the frame formats and...

About the Technical Reviewers

Mark Gallo is a systems engineering manager at Cisco within the Channels organization. He has led several engineering groups responsible for positioning and delivering Cisco end-to-end systems, as well as designing and implementing enterprise LANs and international IP networks. He has a BS in electrical engineering from the University of Pittsburgh and holds CCNP and CCDP certifications. He resides in northern Virginia with his wife, Betsy, and son, Paul. Anthony Sequeira, CCIE No. 15626,...

Enterprise Wanman Architecture Comparison

Enterprise WAN MAN architectures have common characteristics that allow the network designer to compare the advantages and disadvantages of each approach. Table 6-2 compares the characteristics of Private WAN, ISP Service, SP MPLS IP VPN, and Private MPLS architectures. Table 6-2 WAN MAN Architecture Comparison Table 6-2 WAN MAN Architecture Comparison The Cisco Enterprise MAN WAN architecture includes Private WAN, ISP Service, SP MPLS IP VPN, and Private MPLS Private WAN generally consists of...

About the Authors

Anthony Bruno, CCIE No. 2738, is a senior principal consultant with British Telecom with more than 17 years of experience in the internetworking field. Previously, he worked for International Network Services. His other network certifications include CISSP, CCDP, CCVP, and CWNA. He has consulted for many enterprise and service-provider customers in the design, implementation, and optimization of large-scale data and IP telephony networks. He completed his MSEE at the University of...

CCDA Exam Topics

Cisco lists the topics of the CCDA exam on its website at http www.cisco.com web learning le3 current_exams 640-863.html. The list provides key information about what the test covers. Table I-1 lists the CCDA exam topics and the corresponding parts in this book that cover those topics. Each part begins with a list of the topics covered. Use these references as a road map to find the exact materials you need to study to master the CCDA exam topics. Note, however, that all exam information is...

Foreword

CCDA Official Exam Certification Guide, Third Edition, is an excellent self-study resource for the 640-863 DESGN exam. Passing the exam validates your knowledge of network design for Cisco converged networks based on SONA (the Cisco Service-Oriented Network Architecture). Passing the exam is required for the Cisco Certified Design Associate (CCDA) certification. Gaining certification in Cisco technology is key to the continuing educational development of today's networking professional. Through...