A

Procedure used in T1 transmission facilities in which each of the 24 T1 subchannels devotes one bit of every sixth frame to the carrying of supervisory signaling information. Also called 24th channel signaling. AAL. ATM adaptation layer. Service-dependent sublayer of the data link layer. The AAL accepts data from different applications and presents it to the ATM layer in the form of 48-byte ATM payload segments. AALs consist of two sublayers, CS and SAR. AALs differ on...

Acknowledgments

This book would not have been possible without the efforts of many dedicated people. Anthony Bruno would like to thank the following people for their contributions First, thanks to Andrew Cupp, Development Editor, who not only improved the book but also improved me as a writer. I would like to thank Cisco Press Executive Editor John Kane for his vision and guidance of this book. Thanks to the technical editors, David Barnes, Kevin Mahler, and Brian Melzer, whose advice and careful attention to...

Address Formats and Assignment

The current implementation of AppleTalk is Phase 2. Addresses are composed of three elements Network number A 16-bit value assigned by the administrator using the cable-range command. Node number An 8-bit value dynamically assigned that identifies the node. Socket number This 8-bit number identifies the socket running on the node it is similar to a port number in TCP IP. Addresses are written in decimal format, with periods separating the fields. Examples of AppleTalk addresses are 11.2,...

Admission control See traffic policing

ADPCM. adaptive differential pulse code modulation. The process by which analog voice samples are encoded into high-quality digital signals. ADSL . Asymmetric Digital Subscriber Line. One of four DSL technologies. ADSL is designed to deliver more bandwidth downstream (from the central office to the customer site) than upstream. Downstream rates range from 1.5 to 9 Mbps, whereas upstream bandwidth ranges from 16 to 640 kbps. ADSL transmissions work at distances up to 18,000 feet (5,488 meters)...

Cisco Career Certifications

CCNA Exam Certification Guide Wendell Odom, CCIE 0-7357-0073-7 AVAILABLE NOW This book is a comprehensive study tool for CCNA Exam 640-407 and part of a recommended study program from Cisco Systems. CCNA Exam Certification Guide helps you understand and master the exam objectives. Instructor-developed elements and techniques maximize your retention and recall of exam topics, and scenario-based exercises help validate your mastery of the exam objectives. Cisco Systems, Inc., edited by Laura...

B

B channel (bearer channel), 377 B class IP addresses, 201-202, 525-526 subnetting, 202-203 supernetting, 206-207 B8ZS (binary 8-zero substitution), 375 back end nodes, 375 back pressures, 375 backbone areas (OSPF), 215 Backbone routers (OSPF), 217 backbones, 104, 375 backoffs, 375 backplanes, 375 backup links, 114 backup serial lines, 515 backward learning, 375 balanced configuration, 375 balancing loads LocalDirector, 571, 609-611 route redundancy, 111 baluns, 375 bandwidth, 375 bandwidth...

Broadcast and Multicast Behavior

Broadcast behavior is critical to understanding network traffic. Three types of broadcasts and multicasts are covered in this exam Broadcasts and multicasts from desktop protocols, such as AppleTalk, IP, IPX, and NetBIOS Broadcasts and multicasts from servers to advertise their services Broadcasts and multicasts from routing protocols such as RIP The first types of broadcasts are those caused by routed or desktop protocols such as TCP IP, AppleTalk, NetWare, and NetBIOS. For example, when your...

Case Study 1 Answers Cicala and Rosado Law Firm

1 What can be said about the network health of the Ethernet and WAN segments The network health is poor. Ethernet network utilization over 40 percent is not recommended. WAN links over 70 percent utilization should be upgraded to higher speeds. Figure 9-4 shows the existing Cicala and Rosado law firm network. Figure 9-4 Cicala and Rosado Law Firm Existing Network Houston r -C_ 233.10.1.128 26 Dallas 3 What applications are being used Microsoft Office suite applications, WWW and HTTP...

Case Study 1 Cicala and Rosado Law Firm

Kunkel, the IT manager at Cicala and Rosado Law Firm, is responsible for updating the network to use new technologies. He has two network analysts working for him that handle the routers, hubs, clients, servers, and media for the company. The company is understaffed, and the analysts are overworked. There is no network management station monitoring the network. The firm has two locations, one in Houston and one in Dallas, specializing in corporation legalities. A Frame Relay WAN link exists...

Case Study 1 GHY Resources

Martin of GHY Resources is responsible for the company's network. He has invited you to a meeting to discuss some issues. GHY Resources is a manufacturing company with its headquarters based in St. Louis. In the past 10 years, GHY has grown from 10 employees to more than 400. It now has a manufacturing site in Kansas City, and a new site is opening in Nashville, Tennessee, in three months. The manufacturing sites connect back to St. Louis via a 256 K circuit. Sales offices exist in more...

Case Study 2 Pages Magazine Inc

1 What routing protocols are being used at Pages Magazine, Inc. For IP, RIPv1 is being used. For IPX, IPX RIP is being used. For AppleTalk, RTMP is being used. 2 What routing protocol can be recommended to support IP and legacy Novell AppleTalk packets Recommend EIGRP for IP, IPX, and AppleTalk. EIGRP can support VLSM subnetting and can be configured to route IPX and AppleTalk. 3 If the New York City site is expected to grow to more than 150 nodes, what mask would you recommend Recommend a...

Case Study 3 Answers Cartoon Works

1 List the new applications that the customer wants to implement in the network. Video conferencing Novell Internet e-mail system Web servers SQL database DNS Server 2 Draw a logical diagram of the existing network. The customer defined the network by describing the geographical locations and the services that the network provides its users. The logical diagram in Figure 9-6 is based on those services. 3 What type of WAN technology would you recommend as a redundant solution for the T1 between...

Case Study 4 Answers Martin and Martin LLC

1 Draw the corporate structure of this client. Figure 9-7 explains the corporate structure of Martin & Martin, LLC. The diagram shows that there are two main divisions, which are the corporate functions and the legal departments. The chart reflects only information that is specifically stated. 2 What type of testing program would you recommend to test the video conferencing among the remote offices A prototype would be the recommended form of testing because, for the video conferencing to...

Case Study Answers Case Study 1 GHY Resources

Martin mentioned that he does not have the personnel to install and configure UNIX-based management stations. Which network management applications would you recommend to manage his routers and switches CiscoWorks for Windows. CiscoWorks for Windows can be installed on NT platforms, so Mr. Martin does not need UNIX administrators. 2 When preparing the design document, which section are managers must likely to read Executive Summary. This section includes the high-level points for the...

Central office See CO

An AT& T PBX that provides direct inward dialing and automatic number identification of the calling PBX. CEPT. Conference Europenne des Postes et des Telecommunications. An association of the 26 European PTTs that recommends communication specifications to the ITU-T. CERFnet. California Education and Research Federation Network. A TCP IP network, based in Southern California, that connects hundreds of higher-education centers internationally while also providing Internet access to...

Centri Firewall

The Cisco Centri Firewall provides smal-l to medium-sized businesses a strong security solution that is tightly integrated with Windows NT and that is easy to set up and administer. Centri innovative ease-of-use features make it possible to have expert-level security without the expense of onsite security experts. The powerful combination of the Centri Firewall Natural Network Viewer and Policy Builder features make securing a network truly simple for the first time. Security policies can be...

Network Topologies and LAN Design

Do I Know This Already Quiz 99 LAN Topology Design 102 Hierarchical Models 102 Redundant Models 108 Secure Models 115 Large Building LANs 120 Campus LANs 121 Small Remote Site LANs 121 Ethernet Design Rules 122 10 Mbps Fiber Ethernet Design Rules 123 100 Mbps Fast Ethernet Design Rules 124 Token Ring Design Rules 130 Gigabit Ethernet Design Rules 131 FDDI Design Rules 131 LAN Hardware 132 Repeaters 132 Hubs 133 Bridges 133 Switches 134 Routers 135 Layer 3 Switches 136 Combining Hubs, Switches,...

Choosing a Router Platform

You need to provide your client with the right router platform, based on your customer's requirements. Remember to refer back to the Table 5-2 for selecting the right hardware. You will notice that there are many variables that can affect your choice of router platform. For example, the section Provisioning a Frame Relay Network later in this chapter covers provisioning a Frame Relay network and its equipment. The equipment choice depends directly on various factors that are part of the...

Cisco 1000 Series Access Routers

The Cisco 1000 series of compact, easily installed and managed, fixed-configuration desktop routers provides low-cost, high-speed connectivity for branch and small offices. These products offer a range of synchronous and asynchronous WAN options to address a variety of needs and fit seamlessly into any networking environment. Table E-5 lists the products in the Cisco 1000 series. Table E-5 Cisco 1000 Series Product Family Key features of the Cisco 1000 series include the following Support for...

Cisco 1500 Series Micro Hubs

The Cisco 1500 series Micro Hub family provides economical, scalable 10 Mbps hubs for creating LANs in small offices. A single Cisco 1500 Micro Hub can create a LAN that connects up to eight devices. Up to five 10 Mbps hubs can be stacked to create a single manageable stack. The Cisco 1500 series Micro Hub is a member of the Cisco Networked Office Stack, which is designed for small businesses. Table E-27 summarizes the products in the Cisco 1500 series. Table E-27 Cisco 1500 Series Micro Hub...

Cisco Access Router and Access Server Summarization

Tables E-1, E-2, and E-3 summarize the uses and specifications of the various routers and access servers covered in this section. Telecommuter, Small Office, and Home Office Dialup Access Routers Telecommuter, Small Office, and Home Office Dialup Access Routers Small office multiprotocol router for remote access Small office multiprotocol router with integrated hub Remote Office, Branch Office, and Central Site Access Routers Fixed-confi guration desktop routers Modular desktop routers with...

Cisco AS5x00 Universal Access Server Series

The AS5x00 series products are high-performance, medium- to high-density universal access servers that deliver hybrid asynchronous serial and ISDN line service to accommodate both mobile users and high-bandwidth dedicated telecommuters. By terminating both analog modem and ISDN calls on the same chassis from the same trunk line, the AS5x00 enables ISPs and enterprise network managers to meet traditional analog dial access needs while supporting the growing demand for high-speed ISDN access. The...

Cisco Branch Office Connectivity Solutions

Communication becomes challenging for small- and medium-sized companies with branch offices, warehouses, or business partners located in various geographical areas. These companies frequently need to share customer information, check inventory, look up sales data, transfer files, process invoices, and exchange e-mail. The integration of voice and data traffic over shared WAN lines can save companies significant amounts of money. Still, a dispersed organization cannot communicate effectively and...

Cisco Business Solutions

In today's competitive environment, small- to medium-sized businesses need powerful networking solutions to enhance productivity, increase business opportunities, and sustain a competitive edge. Cisco Systems solutions are tailored to meet the needs of customers who want networking solutions that are easy to install, use, and manage. Cost-effective branch office connectivity solutions help increase productivity, allowing small- and medium-sized businesses to stay competitive. These solutions...

Cisco Catalyst 2916M XL

The Catalyst 2916M XL is best when a customer needs the following Any combination of dedicated 10 Mbps or 100 Mbps connections to individual PCs, servers, and other systems, or connectivity between existing Ethernet and Fast Ethernet workgroups The option to easily increase the switch port density and to provide inexpensive higherspeed uplinks through bandwidth aggregation (Fast EtherChannel) Future Gigabit Ethernet and ATM interface modules for higher-speed links VLAN support through a future...

Cisco Config Maker

Cisco ConfigMaker is a Microsoft Windows application used to configure a small network of Cisco routers (800, l000, l600, l700, 2500, 2600, 3600, and 4000 series), switches, hubs, and other network devices from a single PC, without requiring knowledge of Cisco IOS. Cisco ConfigMaker assists in configuring IPSec, IOS Firewall, voice, Network Address Translation (NAT), Committed Access Rate (CAR), Dynamic Host Configuration Protocol (DHCP), and other Cisco IOS features. Cisco ConfigMaker is...

Cisco Fast Step

The Cisco FastStep configuration utility is a Microsoft Windows 95-, 98-, and NT 4.0-based software tool that simplifies the set up, monitoring, and troubleshooting of Cisco routers for home and small offices. The Cisco FastStep Setup application leads the user through a step-by-step, wizard-based procedure that simplifies the configuration of a Cisco router connected to an Internet service provider or to a remote corporate network. Cisco FastStep includes the Cisco FastStep Monitor...

Cisco High Performance LAN Solutions

Small- and medium-sized businesses must be sure that their networks provide quick, reliable access to applications and data, which are the keys to success in today's highly competitive, increasingly global economy. Today's business applications require high-bandwidth networks. Businesses also require more powerful network technologies that are capable of intelligently and efficiently managing traffic flow. Traditional hub-centric LANs can no longer support...

Cisco Micro Webserver

Many small- and medium-sized businesses recognize the potential of Internet marketing. A Web site can market a company and enhance communication. The Cisco Micro Webserver is a Web server appliance that gives small- to medium-sized businesses and branch office customers an easy way to establish an Internet presence or to provide intranet-based intraoffice communications. The Micro Webserver packages both hardware and the embedded Web software kernel within a small footprint for content storage...

Cisco Micro Webserver Customers

The Cisco Micro Webserver is best when a customer needs to accomplish the following To host a Web site on the Internet To publish Web pages on the Internet To facilitate intraoffice communications (Micro Webserver acts as an intranet server) To share information with clients and partners (Micro Webserver acts as an extranet server) To create a Web-based document server To achieve minimal management To achieve low cost of ownership To achieve quick and easy setup and configuration Key benefits...

Cisco Micro Webserver Key Features

The following are the Cisco Micro Webserver key features Stackable, small footprint can be used standalone or stacked with other Cisco Networked Office Stack products. Easy to set up and install, with color-coded cables, Quick Start flow chart, and Administrative Wizard. Real-time HTTP 1.1-compliant kernel that prevents hacking and adds no operating system management overhead. 2.1 GB internal hard drive that enhances Web authoring, content creation, and information dissemination and transfer....

Cisco Works Windows System Requirements

This section overviews the CiscoWorks Windows system requirements. Hardware requirements are as follows Dedicated, Pentium-based IBM PC or compatible computer 24 MB RAM total (32 MB RAM recommended) 45 MB of free disk space for standard installation (130 MB may be needed if SNMPc third-party device support files are installed) CD-ROM drive for installation Super video graphics adapter (SVGA) and color (1024-by-768 pixels and 256 colors are recommended) Network driver interface (NDI) or Open...

Classless Interdomain Routing

Classless interdomain routing (CIDR) is used in Internet Border Gateway Protocol (BGP) routing to reduce the number of Class C routes coming from an autonomous system. For example, ISPs can allocate blocks of 4, 8, or 16 Class C networks to a customer and use only one route for reachability. In Figure 6-3, the client has a CIDR block of four Class C networks, but Router A announces only 208.10.8.0 22 to the ISP router. 192.168.20.0 24 192.168.21.0 24 192.168.22.0 24 192.168.23.0 24 192.168.20.0...

Clear To Send See CTS

A node or software program (front-end device) that requests services from a server. See also back end, front end, and server. client server computing. Computing (processing) network systems in which transaction responsibilities are divided into two parts client (front end) and server (back end). Both terms (client and server) can be applied to software programs or actual computing devices. Also called distributed computing (processing). Compare with peer-to-peer computing. See also RPC....

Combining Hubs Switches and Routers

Network Operating System Diagram

Available in Ethernet and Fast Ethernet, hubs are best used in small networks where there are few nodes on the segment. Hubs do not control the broadcasts nor do they filter collision domains on the network. If higher bandwidth is required, use 100 Mbps hubs. When the number of nodes on the network grows, move to switches. With the cost of switch ports comparable to hubs, use switches as the basic network connectivity devices on the network. Switches reduce collisions and resolve media...

Corporation for Research and Educational Networking See CREN

An indication of how an upper-layer protocol requires that a lower-layer protocol treat its messages. In SNA subarea routing, COS definitions are used by subarea nodes to determine the optimal route to establish a given session. A COS definition comprises a virtual route number and a transmission priority field. Also called TOS (type of service). 2. Corporation for Open Systems. An organization that promulgates the use of OSI protocols through conformance testing,...

D

D channels, 398 D class IP addresses, 201-202 DA (destination address) field Ethernet Version 2 frame format, 542 FDDI (Fiber Distributed Data Interface), 554 Token Ring, 553 DA field (Ethernet), 543 DAC (dual-attached concentrator), 396 DARPA (Defense Advanced Research Projects Agency), 396 DAS (dual attachment station), 396 data channel, see D channel, 396 data compression, 231 Data Encryption Standard (DES), 579 data encryption standard (DES), 119, 396 Data Exchange Interface (DXI), 396 Data...

Data Exchange Interface See DXI

Layer 5 of the SNA architectural model. This layer determines and manages interactions between session partners, particularly data flow. Corresponds to the session layer of the OSI model. See also data link control layer, path control layer, physical control layer, presentation services layer, transaction services layer, and transmission control layer. datagram. A logical grouping of information sent as a network layer unit over a transmission medium without prior...

Design the Local Area Network

The Cisco Certified Design Associate must be able to design local-area networks that meet the customer's objectives on performance and scalability. A CCDA must design networks in a hierarchical manner to provide scalable solutions. A CCDA also must decide where to use hubs, switches, and routers to separate broadcast and collision domains. Know the differences between Layer 2 and Layer 3 switching as well. Chapter 4, Network Topologies and LAN Design, covers this step in more detail. This...

Distance Vector Routing Protocol Comparison

The following CCDA objective is covered in this section 24 Identify scalability constraints and issues for IGRP, EIGRP, IP RIP, IPX RIP SAP, NLSP, AppleTalk RTMP and AURP, static routing, and bridging protocols. Now that all routing protocols have been covered, this section compares the traffic generated by all distance vector routing protocols. Distance vector routing protocols work periodically, sending updates for a specific period of time. Each can carry a certain number of routes on a...

Do I Know This Already Quiz

The questions in the following quiz are designed to help you gauge how well you know the material covered in this chapter. Compare your answers with those found in Appendix A, Answers to Quiz Questions. If you answered most or all of the questions thoroughly and correctly, you might want to skim the chapter and proceed to the Q& A section at the end of the chapter. If you find that you need to review only certain subject matter, search the chapter for those sections that cover the objectives...

Do I Know This Already Quiz Answers

1 Which WAN transport technologies use packet switching to transfer data Frame Relay and X.25 2 What is the line speed of a T3 leased line 44.736 Mbps 3 The Cisco Product Selection Tool can be found where The Cisco Web site (www.cisco.com) or the Cisco documentation CD-ROM 4 If a customer is concerned about the cost of a WAN network, what technology would you recommend for a backup connection to a 128-Kb leased line An ISDN line. An ISDN line is a common cost-effective backup solution because...

Dynamic Host Configuration Protocol

Until the Dynamic Host Configuration Protocol (DHCP) was developed, automatic assignment of IP addresses to hosts was virtually obsolete. The only method available was BOOTP (RFC 0951), which required knowledge of the MAC layer address and preconfiguration of the IP address for a particular MAC on a BOOTP server before the station could get an address. If a station had to be moved from one subnet to another, the BOOTP server had to be reconfigured. DHCP (RFC 2131 1541 1531) solved these...

E

E class IP addresses, 201-202 ED (end delimiter) field FDDI (Fiber Distributed Data Interface), 555 Token Ring, 553 EGPs (Exterior Gateway Protocols), 218 EGPs (exterior gateway protocols) EIGRP (Enhanced Interior Gateway Routing Protocol), 81, 211, 217, 224, 528 electronic commerce, 567 e-mail NetWare MHS (Message Handling Service), 531 networking, 84 encapsulation OSI (Open Systems Interconnection), 512 encoding ASN.1 data types, 258 Manchester encoding, 541 encryption, 230 End stations, 536...

EIGRP for Apple Talk

EIGRP can be used to route AppleTalk packets over a WAN. EIGRP is configured for links between routers RTMP is used on other interfaces. EIGRP sends updates only when changes occur, which represents a significant improvement over the periodic (10-second) RTMP updates. Distance Vector Routing Protocol Comparison 225 Figure 6-7 AppleTalk Update-Based Routing Protocol (AURP) Figure 6-7 AppleTalk Update-Based Routing Protocol (AURP)

Electrostatic discharge See ESD

Enterprise Management Architecture. A Digital Equipment Corporation network management architecture, based on the OSI network management model. 2. Electronic Messaging Association. A forum devoted to standards and policy work, education, and development of electronic messaging systems such as electronic mail, voice mail, and facsimile. EMI. electromagnetic interference. Interference by electromagnetic signals that can cause reduced data integrity and increased error rates on...

Enterprise System Connection channel See ESCON channel

Generally, an individual, manageable network device. Sometimes called an alias. EOT. end of transmission. Generally, a character that signifies the end of a logical group of characters or bits. EPROM. erasable programmable read-only memory. Nonvolatile memory chips that are programmed after they are manufactured and, if necessary, can be erased by some means and reprogrammed. Compare with EEPROM and PROM. equalization. A technique used to compensate for communications channel...

Ethernet Design Rules

Table 4-1 provides scalability information that you can use when provisioning IEEE 802.3 networks. Table 4-1 Scalability Constraints for IEEE 802.3 Table 4-1 Scalability Constraints for IEEE 802.3 (Continued) Table 4-1 Scalability Constraints for IEEE 802.3 (Continued) Maximum Number of Attachments per Segment 2500 meters of 5 segments and 4 repeaters only 3 segments can be populated 2500 meters of 5 segments and 4 repeaters only 3 segments can be populated 2500 meters of 5 segments and 4...

Ethernet Version 2 Frame Format

Figure D-2 shows the Ethernet Version 2 frame format. The remainder of this section discusses the fields in the Ethernet Version 2 frame format. Figure D-2 Ethernet Version 2 Frame Format The preamble is a string of 1s and 0s, ending with 11, to indicate the beginning of the destination address (DA) field. The string of 1s and 0s is used by the transceiver to sync up to the receiving signal. The preamble is as follows 10101010 10101010 10101010 10101010 10101010 10101010 10101010 10101011 The...

Example Network Cabling Implementation

Company ABC has all UTP Category 5 cabling. Two Class II repeaters are separated by 20 meters instead of the standard 5 meters. The network administrators are trying to determine whether this configuration will work. Figure 4-16 An Example Network Cabling Implementation for Company ABC (Showing the Two Most Distant DTEs) 20m UTP Category 5 InterRepeater Link To ensure that the PDV does not exceed 512 bit times, the network administrators must calculate a...

Example of 100BaseT Topology

Figure 4-15 shows examples of 100BaseT topologies with different media. Figure 4-15 Examples of 100BaseT Topologies with Various Media and Repeaters One Class I or II UTP Repeater - 200 meters max Two Class II UTP Repeaters - 205 meters max Two Class II UTP Repeaters - 205 meters max One Class II UTP Fiber Repeater - 308 meters max One Class II UTP Fiber Repeater - 308 meters max One Class II Fiber Repeater - 320 meters max One Class II Fiber Repeater - 320 meters max Other topologies are...

Fast Step Key Features

The following are the Fast Step key features Enables auto-discovery of the router Loads the initial IP address Prefills fields with most common defaults Guides user through entry of LAN WAN parameters, ISDN parameters, and security parameters Makes initial connection to Internet or intranet Monitors items such as call duration, errors, and disconnected calls 4B 5B coding, Fast Ethernet (100BaseT), 547-548 8B 10B coding, Gigabit Ethernet, 549 8-byte 10-byte local fiber, 361 10 Mbps Ethernet...

Fiber Distributed Data Interface

Fiber Distributed Data Interface (FDDI) was developed for the transmission of data over fiber at 100 Mbps. The standard is governed by the American National Standards Institute (ANSI). FDDI is deployed in a dual-ring topology. Each dual-attached station (DAS) attaches to both rings the second ring is on standby. If there is a failure of a station or a link on the ring, a ring wrap occurs, creating a single ring for continued communication. Access to the ring is by the use of a token (as in...

Firewall Services

Pri Voip Interface

The CCDA objectives covered in this section are as follows 8 Determine the customer's requirements for new applications, protocols, number of users, peak usage hours, security, and network management. 9 Diagram the flow of information for new applications. 12 Predict the amount of traffic and the type of traffic caused by the applications, given charts that characterize typical network traffic. A firewall is a system of devices and applications used to protect one network from another untrusted...

Foundation Summary

Foundation Summary is a section presented in a concise format to provide quick reference information relating to the objectives covered in this chapter. Table 7-1 Design Document Components Is directed to decision-makers. Provides an explanation of the purpose of the project, a list of strategic recommendations, and a description of how the solution meets the customer's requirements. Shows current topology, current applications, and current network health. Lists performance and scalability...

Foundation Topics Device Naming Schemes

The following CCDA objective is covered in this section 23 Propose a naming scheme for servers, routers, and user stations. Having the right naming scheme can help the network staff know which device they are using without having to rely on a printed spreadsheet or other outside reference. Naming schemes can be functional or geographical, or they can just follow a random scheme, such as a movie or mythological scheme. For very small networks, you could use a naming system such as Sneezy,...

Foundation Topics WAN Design Considerations

The CCDA objectives covered in this section are the following 2 Assemble Cisco product lines into an end-to-end networking solution. 20 Recommend Cisco products and WAN technologies that will meet the customer's requirements for performance, capacity, and scalability in an enterprise network. There are different requirements when choosing a technology for a WAN than when you are selecting LAN technology. The cost and speed are the critical factors for designing a WAN. WAN connections are high...

G

An ITU-T electrical and mechanical specifications for connections between telephone company equipment and DTE using BNC connectors and operating at E1 data rates. G.804. An ITU-T framing standard that defines the mapping of ATM cells into the physical medium. gateway. In the IP community, an older term referring to a routing device. Today, the term router is used to describe nodes that perform this function, and gateway refers to a special-purpose device that performs an...

H

The capability for data transmission in only one direction at a time between a sending station and a receiving station. Compare with full duplex and simplex. handshake. A sequence of messages exchanged between two or more network devices to ensure transmission synchronization. HBD3. A line code type used on E1 circuits. H channel. high-speed channel. A full-duplex ISDN primary rate channel operating at 384 kbps. Compare with B channel, D channel, and E channel. HDLC. High-Level...

Hierarchical Model Examples

For small- to medium-sized companies, the hierarchical model is often implemented as a hub-and-spoke topology, as shown in Figure 4-2. Corporate headquarters forms the hub and links to the remote offices form the spokes. Figure 4-2 The Hierarchical Model Is Often Implemented as a Hub-and-Spoke Topology Figure 4-2 The Hierarchical Model Is Often Implemented as a Hub-and-Spoke Topology You can implement the hierarchical model by using either routers or switches. Figure 4-3 is an example of a...

Hierarchical versus Flat Designs

The CCDA should understand that there is a limit on the number of nodes in flat network designs. Network broadcasts can overcome slow serial links. Build the network in a hierarchical manner with subnetting to reduce the amount of traffic on WAN links. The CCDA must understand the three layers of the hierarchical model for network design the core, distribution, and access layers. Figure 1-4 provides an example of these three layers. At the core layer, high-speed switching is used with high...

IBM Systems Network Architecture Protocols

IBM networking today consists of essentially two separate architectures that branch from a common origin. Before contemporary networks existed, IBM's Systems Network Architecture (SNA) ruled the networking landscape, so it is often referred to as traditional or legacy SNA. With the rise of personal computers, workstations, and client server computing, the need for a peer-based networking strategy was addressed by IBM with the creation of Advanced Peer-to-Peer Networking (APPN) and Advanced...

IP Address Classes

IP addressing defines five address classes A, B, C, D, and E. Only classes A, B, and C are available for addressing devices class D is used for multicast groups, and class E is reserved for experimental use. The first octet of an address defines its class, as illustrated in Table C-1. This table also shows the format of the addresses in each class as defined by the network bits (N) and host bits (H). Table C-1 IP Address Classes A, B, and C Are Available for Addressing Devices Table C-1 IP...

IP Routing Protocol Administrative Distance

On routers running several routing protocols, the possibility exists that two different routing protocols have a route to a destination. Cisco routers assign each routing protocol an administrative distance, which by default is as show in Table 6-15. The lower the administrative distance, the more preferred that route will be. For example, say that a router has a route in EIGRP for network 172.20.10.0 24 with the best path out Ethernet 0, and has a route in OSPF for network 172.20.10.0 24 with...

Link State Advertisement Types

OSPF defines different link-state advertisement (LSA) types for router, network, summary, external, and so on. Table 6-14 describes the major LSA types. Produced by every router and includes all the router's links, interfaces, state of links, and cost. Produced by every designated router (DR) on every transit broadcast or nonbroadcast multiaccess (NBMA) network. It lists all attached routers in the multiaccess network. Produced by area border routers (ABRs). It is sent into an area to advertise...

M

The lower of the two sublayers of the data link layer defined by the IEEE. The MAC sublayer handles access to shared media, such as whether token passing or contention will be used. See also data link layer and LLC. MAC address. A standardized data link layer address that is required for every port or device that connects to a LAN. Other devices in the network use these addresses to locate specific ports in the network and to create and update routing tables and data...

Mbps Fiber Ethernet Design Rules

Table 4-2 provides some guidelines to help you choose the right media for your network designs. 10BaseF is based on the fiber-optic interrepeater link (FOIRL) specification, which includes 10BaseFP, 10BaseFB, 10BaseFL, and a revised FOIRL standard. The new FOIRL allows data terminal equipment (DTE) end-node connections rather than just repeaters, which were allowed with the older FOIRL specification. Table 4-2 Scalability Constraints for 10 Mbps Fiber Ethernet allows data terminal equipment...

Netsys Connectivity Tools

The Netsys Connectivity Service Manager enables you to view, assess, and troubleshoot a full spectrum of connectivity issues, including network availability, security, and reliability. It monitors the actual network configuration data and uses built-in intelligence to verify the availability of key network services. It also enables you to establish service-level policies for connectivity, reliability, and security services, and it uses the unique VISTA (view, isolate, solve, test, apply)...

Netsys Performance Tools

The Netsys Performance Service Manager complements the capabilities of the Netsys Connectivity Service Manager, enabling you to define, monitor, and optimize performance service levels to make the most efficient use of existing network resources to diagnose and solve network performance problems to tune existing networks and to plan network changes. This product is the only Cisco-certified performance-modeling application on the market. By providing accurate modeling of routing and flow...

Net Ware Link Services Protocol

IPX RIP and SAP each produce periodic broadcasts every 60 seconds, adding significant traffic to the network. NetWare Link-Services Protocol (NLSP) is a link-state routing protocol designed to overcome the limitations of RIP SAP. NLSP has characteristics similar to other link-state protocols link-state advertisements are generated by routers and are flooded throughout the network, and each router computes best paths to destinations. Updates are sent only when required. NSLP also supports up to...

Net Ware Protocol Suite

NetWare is a network operating system (NOS) that provides transparent remote file access and numerous other distributed network services, including printer sharing and support for various applications, such as electronic mail transfer and database access. NetWare specifies the upper five layers of the OSI reference model and, as such, runs on virtually any media-access protocol (layer 2). Additionally, NetWare runs on virtually any kind of computer system, from PCs to mainframes. Introduced in...

Objectives Covered in This Chapter

The following is a list of the objectives covered in this chapter. The list of all the CCDA exam objectives and the chapters in which they are covered can be found in the Introduction of this book. Identify all the data you should gather to characterize the customer's existing network. Document the customer's current applications, protocols, topology, and number of users. Document the customer's business issues that are relevant to a network design project. Assess the health of the customer's...

OSPF Router Types

OSPF introduces several router types related to their place in the area architecture. Figure 6-5 displays a diagram of OSPF router types. The following is a list of explanations for each router type shown in Figure 6-5 Internal router All routers whose interfaces belong to the same OSPF area. These routers keep only one link-state database. Area border router (ABR) Routers that are connected to more than one area. These routers maintain a link-state database for each area to which they belong....

Packet Voice

With the converging of data and voice networks, the introduction of packet voice technology provides the means for companies to save toll charges on voice telephone calls. Voice is digitized into packets, cells, or frames, is sent as data throughout the networks, and is then converted back to analog voice (see Figure 3-10). Calls are placed on telephones attached to routers. The routers digitize the voice and then forward the calls on the WAN links. If it is determined that sufficient bandwidth...

QA Answers

1 What session layer protocol is common in Windows NT environments when layered over TCP it can be routed 2 You can find WWW and FTP servers in what network that the Internet community can 3 What is a method to reduce Novell SAP broadcast traffic on the network Use Enhanced IGRP, SAP filters, and NLSP. 4 HTTP is an example of what type of traffic flow Client server 5 What access list would you use on an outside filtering router to permit access to the isolation LAN Assume the isolation LAN is...

R

RARP (Reverse Address Resolution Protocol), 523 rate-sensitive traffic, 529 RDP, workstation-to-router redundancy, 109 read command (SNMP), 255, 537 Real-Time Transport Protocol (RTP), 78 receivers (RSVP sessions), 529 RED (Random Early Detection), 580 redundancy LANs, 108-115 media, 113-115 route redundancy, 111-113 server redundancy, 110-111 workstation-to-router redundancy, 108-110 WANs hardware, 168 topologies, 158-160 redundant star configuration, 160 Relative Network Utilization,...

Resource Reservation Protocol

The Resource Reservation Protocol (RSVP) is a network control protocol that enables Internet applications to obtain special qualities of service (QoSs) for their data flows. RSVP is not a routing protocol instead, it works in conjunction with routing protocols and installs the equivalent of dynamic access lists along the routes that routing protocols calculate. RSVP occupies the place of a transport protocol in the OSI seven-layer model. In RSVP, a data flow is a sequence of messages that have...

Routing Information Protocol

Routing Information Protocol (RIP) version 1 is defined in RFC 1058. This is a distance vector routing protocol that uses hop count as a metric. The maximum hop count is 15, with 16 registering as unreachable. RIP is a classfull protocol and does not support VLSM or authentication. RIP routers send updates to their neighbors every 30 seconds. RIP was designed for smaller networks, usually implemented in UNIX environments. RIP routers expect to see routes from their neighbors every 30 seconds....

Routing Table Maintenance Protocol

Routing Table Maintenance Protocol (RTMP) is the distance vector routing protocol for forwarding AppleTalk packets. RTMP is based on RIP, uses hop count as the metric, and has the same limitation of 15 hops. Routing table updates are sent in periodic fashion. The table contains the following information for each of the destination routes known to the router Network cable range of the destination network Distance, in hops, to the destination network Router port that leads to the destination...

S

An FDDI or CDDI concentrator that connects to the network by being cascaded from the master port of another FDDI or CDDI concentrator. sampling rate. The rate at which samples of a particular waveform amplitude are taken. SAP. 1. service access point. A field defined by the IEEE 802.2 specification that is part of an address specification. Thus, the destination plus the DSAP define the recipient of a packet. The same applies to the SSAP. See also DSAP and...

Secure Models

This section introduces secure topology models. The information in this book is not sufficient to learn all the nuances of internetwork security. To learn more about internetwork security, you might want to read the book Firewalls and Internet Security, by Bill Cheswick and Steve Bellovin, published by Addison Wesley. Also, by searching for the word security on Cisco's web site (www.cisco.com), you can keep up to date on security issues. Secure topologies are often designed by using a firewall....

Selecting a WAN Technology

The CCDA objectives covered in this section are the following 18 Recognize scalability constraints and issues for standard WAN 20 Recommend Cisco products and WAN technologies that will meet the customer's requirements for performance, capacity, and scalability in an enterprise network. To simplify the process for choosing the right WAN technology, Table 5-1 summarizes important aspects of common WAN technologies into a reference chart. Table 5-1 contains information on which technology is the...

Selecting the WAN Hardware

The CCDA objectives covered in this section are the following 19 Recognize scalability constraints and performance budgets for major Cisco products. 20 Recommend Cisco products and WAN technologies that will meet the customer's requirements for performance, capacity, and scalability in an enterprise network. Throughout this book there are checklists with questions and criteria to aid a designer in selecting a technology or method. Table 5-2 summarizes the criteria you need to understand to meet...

SNMPv2 Protocol Data Unit PDU

SNMPv2 specifies two PDU formats, depending on the SNMP protocol operation. SNMPv2 PDU fields are variable in length, as prescribed by ASN.1. Figure 7-8 illustrates the fields of the SNMPv2 Get, GetNext, Inform, Response, Set, and Trap The following descriptions summarize the fields illustrated in Figure 7-8 PDU Type Identifies the type of PDU transmitted (Get, GetNext, Inform, Response, Set, or Trap). Request ID Associates SNMP requests with responses. Error Status Indicates one of a number of...

SNMPvl Protocol Operations

SNMP is a simple request-response protocol. The network-management system issues a request, and managed devices return responses. This behavior is implemented by using one of four protocol operations Get, GetNext, Set, and Trap. The Get operation is used by the NMS to retrieve the value of one or more object instances from an agent. If the agent responding to the Get operation cannot provide values for all the object instances in a list, it does not provide any values. The GetNext operation is...

Source Route Bridging

IBM developed SRB in the mid-eighties as a way to bridge between Token Ring local-area networks (LANs). In SRB, the source determines the route to arrive at the destination node before sending an information frame to it. This differs from Ethernet transparent bridging, where the bridges build and maintain tables containing paths to data-link layer destinations. In SRB, the source node acquires the routes to destinations on the network using explorer frames. In Figure 3-1, when a source node...

Step 1 Characterize the Customers Application

The existing applications are a critical part of the assessment because applications are an enduser service. This means that application documentation must be accurate and detailed because each segment and each application can have unique qualities. Create a table with the fields displayed in Table 2-1 to document the customer's applications. Remember that a good analysis of the customer's requirements can help you narrow the applications you need to document. Table 2-1 Fields for Documenting...

Step 1 Review the Customers Requirements

Having a clear goal for building your prototype is essential. In fact, the prototype design should be created using the same approach you used to determine customer requirements for the original design. Refer back to Chapter 2, Assessing the Existing Network and Identifying Customer Objectives, if you need to review the list of requirements. First, list the customer's major goals. Then identify the customer's requirements for performance, security, capacity, and scalability. Also consider other...

Step 12 Summarize the Health of the Existing Network

The network health checklist presented in Table 2-6 can help you make some quick assessments on the overall health of the network Although these numbers are guidelines, it's important for the exam that you refer to these guidelines when answering the questions. Many guidelines need to be tempered by taking into account the environment you are comparing. Therefore, when you compare your findings to the health list, remember to also document the reason for the deviation. No shared Ethernet...

Step 8 Characterize the Existing Network Reliability

Both Step 8, Characterize the Existing Network Reliability, and Step 9, Characterize Network Utilization, require understanding network traffic to capture accurate data. The section Step 4 Identify Potential Bottlenecks, earlier in this chapter, introduced some tools that help characterize the customer's network. Documenting network traffic can be the most time-consuming of all the data collections. This is primarily due to the time you need to devote to each segment to get accurate data....

Step 9 Characterize the Network Utilization

Characterizing the network utilization can easily be done with a network management tool. You just need to configure the monitoring tool to the time settings to gather the data, and the tool will do it for you automatically. You can gather data for every protocol and segment and even break down the sampling of protocols such as TCP IP into TCP and UDP protocols. This would be useful in tracking different types of applications the granularity of the sampling is really dependent on need. Peak...

T

T1 transmits DS-1-formatted data at 1.544 Mbps through the telephone-switching network, using AMI or B8ZS coding. Compare with E1. See also AMI, B8ZS, and DS-1. T3. A digital WAN carrier facility. T3 transmits DS-3-formatted data at 44.736 Mbps through the telephone switching network. Compare with E3. See also DS-3. TAC. Terminal Access Controller. An Internet host that accepts terminal connections from dial-up lines. TACACS. Terminal Access Controller Access...

Test the Design

After a design has been proposed, the next step is to verify that the design will work. For large networks, a prototype can be built for smaller networks a pilot can be devised. Chapter 8, Building a Prototype or Pilot, covers the steps of building prototype and pilot test networks. The following questions are designed to test your understanding of the topics covered in this chapter. When you have answered the questions, look up the answers in Appendix A, Answers to Quiz Questions. After you...

Token Ring Frame Format

There are two types of frame formats data command frames and token frames. These frames are displayed in Figures D-12 and D-13. Tokens are 3 bytes in length and consist of a start delimiter, an access control byte, and an end delimiter. Data command frames vary in size, depending on the size of the information field. Command frames contain control information and do not carry upper-layer protocols. The following is an explanation of the fields in Figures D-12 and D-13 SD (starting delimiter)...

Transparent Bridging Scalability Issues

Bpdu Frames

A transparent bridge floods all multicast frames, broadcast frames, and frames with an unknown destination address out every port except the one on which the frame was received. Broadcasts and multicast create scalability issues that can be controlled only with routing. Transparent bridges implement the Spanning-Tree Algorithm, which is specified in IEEE 802.1d. In the sample network in Figure 6-8, the Spanning-Tree Protocol states that only one active path exists between two stations. If a...

U

Universal Asynchronous Receiver Transmitter. An integrated circuit, attached to the parallel bus of a computer, used for serial communications. The UART translates between serial and parallel signals, provides transmission clocking, and buffers data sent to or from the computer. UB Net One. Ungermann-Bass Net One. A routing protocol, developed by UB Networks, that uses hello packets and a path-delay metric, with end nodes communicating using the XNS protocol. There are a number of...

Using Cisco IOS Commands to Test the Prototype or Pilot

Table 8-5 lists the recommended IOS commands and the results they would yield. These are only a subset of the Cisco IOS commands that are available for a full listing of Cisco IOS commands, refer to the CCO Web site or the Cisco Documentation CD-ROM. Table 8-5 Cisco IOS Commands Used for Testing a Prototype or Pilot Shows data link layer errors, router errors (such as dropped or ignored packets), and broadcast rates Shows router CPU usage and CPU time used by processes Is used to troubleshoot...

V

An ITU-T standard for a physical layer interface between DTE and DCE. V.24 is essentially the same as the EIA TIA-232 standard. See also EIA TIA-232. V.25bis. An ITU-T specification describing procedures for call setup and teardown over the DTE-DCE interface in a PSDN. V.32. An ITU-T standard serial line protocol for bidirectional data transmissions at speeds of 4.8 or 9.6 kbps. See also V.32bis. V.32bis. An ITU-T standard that extends V.32 to speeds up to 14.4 kbps. See also V.32. V.34....

WAN Dialup Services

Dialup services offer cost-effective methods for connectivity across WANs. Two popular dialup implementations follow Dial-on-demand routing (DDR) A technique whereby a router can dynamically initiate and close a circuit-switched session as transmitting end stations demand. A router is configured to consider certain traffic interesting (such as traffic from a particular protocol) and other traffic uninteresting. When the router receives interesting traffic destined for a remote network, a...

Warning and Disclaimer

This book is designed to provide information about the CCDA examination. Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness is implied. The information is provided on an as is basis. The author, Cisco Press, and Cisco Systems, Inc., shall have neither liability nor responsibility to any person or entity with respect to any loss or damages arising from the information contained in this book or from the use of the discs or programs...