Physical Layout and Prestaging

Connect the hubs and serial cables to the routers, as shown in Figure 17-8. Use HDLC as the WAN protocol. Connect the three Ethernet hubs to the routers to form three LAN segments, as shown in Figure 17-8. Configure EIGRP across the network, use 2001 as the Autonomous System ID. Add and configure the NTP server on the Ethernet segment of the ticket_central router. Enable NTP broadcast, and set the stratum level to 3 on the software. The IP address of the server is 206.191.241.45. Lab 35...

About the Authors

Karl Solie, CCIE 4599, is a principal network engineer for Comdisco Inc. Karl has more than 13 years of experience in the field designing and implementing LAN WAN-based networks internally and externally for McDonnell Douglas, Unisys, and Comdisco. Over the past 13 years, Karl has worked on a vast array of internetworks, including some of the largest commercial and government-based IP and SNA networks in the United States. He has performed LAN WAN design and implementation on networks ranging...

Acknowledgments

This book would not have been possible without the dedication of many friends, CCIEs, and other professionals. First and foremost, I would like to thank the team at Cisco Press for their never-ending encouragement over the past two years. I especially would like to thank John Kane for his belief in me and for bringing the project to fruition. I would also like to thank Amy Lewis for her cheerful support and guidance over the past two years. I would like to acknowledge Chris Cleveland as well,...

Additional Commands for Configuring Frame Relay

Some additional commands are available to control or modify your Frame Relay network. The following list includes some of the more commonly tuned features of Frame Relay. For a complete list, see the IOS WAN Configuration Guide. Router(config-if)no frame-relay inverse-arp Disables the sending of Inverse ARP requests. Use this command in conjunction with no arp frame-relay to prevent the dynamic mapping of PVCs. Router(config-if)no arp frame-relay Disables ARP responses. Use this in conjunction...

After Summarization

Caution should be used whenever redistributing one routing protocol into another. Potential routing loops can occur if there are two or more redistribution points within the network. When multiple redistribution points are in the network, distance vector protocols are vulnerable to loops. Use the route maps with a well-thought-out IP addressing scheme to control loops. Whenever you are working with routing protocols that don't carry a subnet mask within the routing update, such as RIP-1 and...

Appendix B The Abridged OSI Reference Model

Almost every book on networking has some reference to the OSI reference model this one will be no exception. However, instead of repeating the same text that you've probably already read 50 times, I would like to offer a new twist on the model in Table B-1. This information is presented here in less then 10 words per level, as an abridged OSI reference model. To read unabridged versions, refer to Interconnections, Second Edition Bridges, Routers, Switches, and Internetworking Protocols by Radia...

Appendix C Rfc List

Table C-1 provides a list of some of the more common RFCs found throughout the text. The complete text version of these RFCs can be found at www.isi.edu. The PPP Bandwidth Allocation Protocol (BAP) The PPP Bandwidth Allocation Control Protocol (BACP) Simple Network Time Protocol (SNTP) Version 4 for IPv4, IPv6 and OSI TCP Selective Acknowledgment Options PPP Challenge Handshake Authentication Protocol (CHAP) Address Allocation for Private Internets Management Information Base for version 2 of...

Appendix D Common Cable Types and Pinouts

This appendix provides the following pinout information Console Port Pinouts (RJ-45) Auxiliary Port Pinouts (RJ-45) EIA-530 DTE Cable Pinout (DB-60 to DB-25) EIA TIA-232 DTE Cable Pinout (DB-60 to DB-25) EIA TIA-232 DCE Cable Pinout (DB-60 to DB-25) EIA TIA-449 DTE Cable Pinout (DB-60 to DB-37) EIA TIA-449 DCE Cable Pinout (DB-60 to DB-37) V.35 DTE Cable Pinout (DB-60 to 34-Pin) V.35 DCE Cable Pinout (DB-60 to 34-Pin) X.21 DTE Cable Pinout (DB-60 to DB-15) X.21 DCE Cable Pinout (DB-60 to DB-15)...

BaseLX Gigabit Ethernet

LX GBICs use a laser-based wavelength of 1300 nms. Depending on the cable type, LX GBIC operate at distances of 550 m to 5000 m, as listed in Table 2-4. Cisco also supports an LH and LX GBIC, which extends the IEEE 1000Base-LX maximum distance of 5 km. Table 2-4. 1000Base-LX Cable Limitations Table 2-4. 1000Base-LX Cable Limitations

BaseSX Gigabit Ethernet

1000Base-SX GBICs use a laser-based wavelength of 850 nms. Depending on the cable type, SX GBIC operates at distances of 220 m to 550 m, as listed in Table 2-3. Wavelengths up to 850 nm are visible to the human eye. Table 2-3. 1000Base-SX Cable Limitations Table 2-3. 1000Base-SX Cable Limitations

Broadcast Domains and Collision Domains

Two key concepts in switched networks are broadcast domains and collision domains. A broadcast domain is the area of the network that forwards broadcasts from one portion of network to the next. A practical example of a broadcast domain is an IP or IPX subnet. A collision domain is a function of the physical properties of a device. Devices in the same collision domain reside on the same wire or hub repeater. Table 2-8 illustrates how various network devices segment collision and broadcast...

Channel Signaling Types and Frame Formats

Digital service level 0 (DS-0) is the smallest unit of transmission in the hierarchy. It is a 64-kbps circuit. A DS-0 channel can carry one digital PCM voice call. A total of 24 DS-0s can be multiplexed together to form the next level, called a DS1. A digital service level 1 (DS-1) is a 1.544-Mbps circuit. A DS1 carries 24 8-bit byte DS-0s at 1.544 Mbps. A DS-1 frame is 193 bits long, containing 8 bits from each of the 24 DS-0s, plus 1 framing bit. The two major framing formats for T1 are D4...

The Key Components for Modeling an Internetwork

Many types of models exist today, from mathematical models and statistical models to the plastic models that you might have built when you were young. Despite their vast differences, they all are models of one type. This book proposes a new kind of model the internetwork model. The internetwork model will be defined as a smaller accurate and functional representation of a larger internetwork. Internetwork models, as with all models, are smaller representations of larger networks. The word...

Distance Vector Protocols Interior Gateway Routing Protocol IGRP

When Cisco Systems developed the Interior Gateway Routing Protocol (IGRP) around 1986, network administrators didn't have many options to deal with some of RIP's limitations. RIP's hop-count limit of 15 and its simplistic metrics weren't allowing networks to scale and distribute traffic across paths of unequal cost. OSPF would not come out for another two years, and another routing protocol was needed. As the pioneer of internetworking, Cisco developed IGRP to specifically address some of RIP's...

Hybrid Enhanced Interior Gateway Routing Protocol EIGRP

As internetworks grew in scale and diversity in the early 1990s, new routing protocols were needed. Cisco developed Enhanced Interior Gateway Routing Protocol (IGRP) primarily to address many of the limitations of IGRP and RIP. As WANs were growing, so was the need for a routing protocol that would use efficient address space on WAN links, as well as the LAN networks. OSPF was available, but the CPU-intensive tasks that it had to perform often overloaded the small processors of many edge or...

Link State Protocols Open Shortest Path First OSPF

Since its conception in 1987, OSPF has continued to evolve with the modern internetwork. Today, OSPF is clearly the dominant Open Systems interior routing protocol. Because of the constant RFC enhancements to OSPF, it has proven itself to be a scalable protocol with networks in the tens of thousands of nodes. OSPF officially was documented in 1989 by the Internet Engineering Task Force (IETF) to address many of the limitations of distance vector protocols, such as RIP and IGRP. Since 1989, OSPF...

Configuring Bridging and Data Link Switching Plus

Most of the early protocols were designed without explicit network addresses. For that reason, the protocol does not have the same concept of traditional Layer 3 that we have grown to love. Protocols without explicit network layer addresses, by definition, are called nonroutable or bridged protocols. Some examples of common bridged protocols are IBM Systems Network Architecture (SNA), NetBEUI, NetBIOS, and DEC LAT. The most commonly used bridged protocols today are SNA and NetBEUI. IBM's SNA is...

Understanding IP Access Lists

In many modern networks, there eventually comes a point when full IP reachability is no longer desirable. The reasons for this can range from security concerns to political concerns, such as the merging of two companies with the same IP address space assigned. And sooner, or later, the request will come Can we just allow , and you will be forced to deal with access lists. Controlling routing updates, traffic paths, and protocols can be one of the more challenging aspects of router...

Configuring Network Address Translation NAT

The phenomenal growth of the Internet spawned a tremendous squeeze on IP address space. Some of the stronger solutions offered to relieve this pressure are classless interdomain routing (CIDR) and IPv6. CIDR can be viewed as the short-term solution until IPv6 becomes the dominant version of IP in use. But many private networks and ISPs have yet to migrate to IPv6. Perhaps one reason for the delay to migrate to IPv6 is the huge success of an intermediate solution called Network Address...

Configuring Network Time Protocol NTP and Simple Network Time Protocol SNTP

Bob poured feverishly over the latest trace of the chronic link problem. There was a strong chance that it was this same problem that they had experienced just one week earlier. Bob wasn't his real name it was a name that all the guys called him because he was the new guy. Bob knew almost every acronym in the Telco industry, and he also knew that the ATM was indeed faster then Ethernet. In the middle of his spaghetti network, he had finally found a smoking gun. He would finally prove his worth...

LAN Protocols Configuring Catalyst Ethernet and Token Ring Switches

In the realm of networking, no technology is outpacing that of local-area networks (LANs). In less than a decade, LANs have become common in many homes and are a must for any small business. Many, if not all, new commercial buildings are wired with some type of copper or fiber cable plant for local-area networking. Even when you travel, many hotels offer the use of a LAN to access the Internet. Many new residential communities are incorporating what you might call community-area networks, or...

WAN Protocols and Technologies Pointto Point Protocol PPP

Along with the explosion of the Internet came the explosion of the Internet's access protocol, the Point-to-Point Protocol (PPP). Most analog dialup connections today run PPP as their datalink protocol. This is primarily because of the Internet-friendly capabilities of PPP Network layer address negotiation Authentication using CHAP or PAP Before PPP became the dominant Internet access protocol, it was often used and confused with the Serial Line Internet Protocol (SLIP). Many people commonly...

WAN Protocols and Technologies Frame Relay

Frame Relay has become king of the WAN over the past five to seven years. Many private networks have gone through lengthy migration processes, moving from point-to-point serial links to Frame Relay-based networks. As popular as Frame Relay is, its popularity is starting to wane. Frame Relay circuits eventually might be replaced by lower-cost, higher-speed circuits, such as DSL or cable modems. If a home user can get T3 speed access to Internet service providers (ISP), it is only a matter of...

WAN Protocols and Technologies Asynchronous Transfer Mode ATM

Authoring contribution by Galina Diker Pildush Asynchronous Transfer Mode (ATM) has been looked upon as the technology that can do it all carry voice, data, and video information, implying that both voice and data payloads, batch and real-time, can be transferred from one part of the world to another. This is implemented with guarantees in quality, such as integrity of the information and its throughput, toward different classes of services. In my book Cisco ATM Solutions, I elaborate on the...

Distance Vector Protocols Routing Information Protocol Versions 1 and 2 RIP1 and RIP2

As IP-based networks enter the 21st century, one of the earliest routing protocols is still present in many modern networks. For good reason, RIP has managed to survive from the creation of IP to the present. This proves one thing about RIP despite its limitations, it performs its job well. RIP has evolved over the years from a classful routing protocol, RIP Version 1 (RIP-1), to a classless routing protocol, RIP Version 2 (RIP-2). This chapter covers the operation, configuration, and tuning of...

Cisco 7200

The Cisco 7200 series provides both enterprise and service provider customers with a choice of either a four- or a six-slot chassis. The 7200 provides service providers with the foundation for managed router and managed network services with multiservice for data, voice, and video integration. The 7200 extends the multiservice capabilities to support VoIP services, as well as voice-processing extensions such as voice compression and PBX signaling. The 7200 supports multiservice aggregation of...

Cisco [OS PlannerWW

Ov Cd< -i IOS ilinKi ttti m .ir fktbufV h WK I Y--m -r icl-ncd J Jj 1. i c ar u I iit-Jlj j-.nl r.r m . i rtkut ri 1 lmrr > r J 1 - mkr c vu J d t c SfUn --r Jzr f j Ini.itt tt-if A rr-ijcm i rr I. A. p jHaor-j. mi * EfeBW r. J t,.jH- L-fi-jUrr I. Ti 11- Lrt- -n. a - r ltw. '-r F-fhi-j.- friftrr J-i iri ri 4 efcr ccrv < h vci tur-J n jvm K-k rlv'-r urti v v wrv-, ' y.-w r rrlrr 1 t--.y F -J tjtf.Kr uf tvirc 1 riftwi f i .TiTii- ri'. rrr.cn so iyjil I , n-t i* Hkt+cv fcilr* II f i 'nvr...

Classful Routing RIP1 Only

RIP-1 is a classful routing protocol, so it does not advertise a subnet mask along with advertised routes. For RIP to determine what the subnet mask is of the destination network, RIP uses the subnet mask of the interface in which the route was received. This is true only if the route received is a member of a directly connected major network. If the route received is not of the same major network, the router tries to match only the major bit boundary of the route either Class A, B, or C. For...

Classless Routing RIP2 Only

RIP-2 is not a new routing protocol, but it is an extension of RIP-1 provided by RFCs 1721, 1722, and 1723. The extensions provide the following enhancements to RIP VLSM support. The router carries the subnet mask in the update, which allows the router to handle VLSM addressing. A next-hop address carried with each route entry. Support for external route tags. Support for MD5 authentication. The most significant of all the enhancements is the support for VLSM, making RIP-2 a classless routing...

Clearing and Changing NAT Translations

NAT TCP translations will time out after a default of 24 hours. You can change the timeout values on a per-protocol basis with the following commands ip nat translation timeout seconds Specifies the timeout value that applies to dynamic translation, except for ones with overload translations. The default is 86,400 seconds, or 24 hours. ip nat translation udp-timeout seconds Specifies the timeout value of UDP translations. The default is 300 seconds, or 5 minutes. ip nat translation dns-timeout...

Command Syntax Conventions

The conventions used to present command syntax in this book are the same conventions used in the Cisco IOS Command Reference. The Command Reference describes these conventions as follows Vertical bars ( ) separate alternative, mutually exclusive elements. Square brackets indicate optional elements. Braces indicate a required choice. Braces within brackets indicate a required choice within an optional element. Boldface indicates commands and keywords that are entered literally as shown. In...

Commands to Control Route Filtering Redistribution

To call a standard access list to filter inbound routing updates, use the following command Router(config-router)distribute-list 2-55 in interface name The in option is applied from the view of the interface. In other words, to prevent a routing update from entering an interface, use the in option. This command filters only the route, not the LSA. To redistribute other routing protocols into OSPF, use the following command Router(config-router)redistribute connected static bgp rip igrp eigrp...

Common Protocols

Network layer protocols, such as IP, IPX, and AppleTalk Other RFCs significant to PPP are listed here RFC 1144 TCP IP header compression. RFC 1220 Point-to-Point Protocol extensions for bridging. This RFC replaces RFC 1220. RFC 1334 PPP authentication protocols. RFC 1378 PPP AppleTalk Control Protocol (ATCP). RFC 1552 PPP Internetworking Packet Exchange Control Protocol (IPXCP). RFC 1570 PPP LCP extensions. RFC 1661 Point-to-Point Protocol (PPP). RFC 1662 PPP in HDLC-like framing. RFC 1990 PPP...

Configuration

Interface BRIO ip address 175.10.23.3 255.255.255.248 encapsulation ppp isdn spidl 61293193601111 isdn spid2 61293197761111 dialer map ip 175.10.23.1 name Cheech broadcast 6129319937 dialer map ip 175.10.23.2 name Chong broadcast 6129319833 dialer-group 1 The configuration in Example 7-4 enables the passing of routing updates and other broadcast traffic. However, if you don't want this traffic to actually trigger calls, you need to specify restrictive dialer lists or make the ISDN interface...

Configuring Analog Remote Access

Remote access to a network can be considerably useful during your studies and in the field. The Cisco TAC often asks if an analog modem is attached, to help in troubleshooting your problem. Problem solving can be significantly easier when another person can get a firsthand view of the problem. Being able to troubleshoot from a remote location with this type of an out-of-band connection alone can be invaluable. The sections presented here are intended to arm you with enough knowledge to...

Configuring and Using the Access Server

The access server provides out-of-band configuration to several devices at a single time. At a large site where several key routers and switches are located, an access server provides the best method for configuration access. You use the access server to configure the routers and switches in the upcoming lab. The configuration of the access server requires a logical tie between an IP address and a TTY session. To configure what Cisco refers to as reverse Telnet, you need to configure three...

Configuring Catalyst Ethernet Switches

The colorful history of Ethernet switching is present in the Catalyst line. Each family of Catalyst switches has a slightly different command-line interface. The Catalyst switches such as the 1900 and 2800 come from Grand Junction and have one type of configuration interface and method. The Catalyst 3000 originated with Kalpana and has another method of configuration. The Catalyst 5500 family started with Cisco's acquisition of Crescendo. The Catalyst 5500 and 6500 families have a unique...

Configuring Dialon Demand Routing DDR

For ISDN to work properly, dial-on-demand routing (DDR) options must be created on the interface. Often, ISDN links are used to back up point-to-point or Frame Relay circuits. If not configured correctly, the ISDN link can stay up constantly or can continuously connect, hang up, and then connect again. Because ISDN carrier's normally charge usage by the minute, a small configuration error can result in a customer getting ISDN bills of more than 1000 per month. Unless you enjoy long discussions...

Configuring DLSw Reachability with the icanreach Command

During the DLSw+ capabilities exchange, routers also exchange what resources they can reach in the control vectors. This is information that can be statically configured on the router. By configuring what SAP, MAC address, and NetBIOS names the router can reach, it can greatly reduce the number of explorers sent to remote peers. Along with the resources that the router can reach, you can configure the SAP values that the router cannot reach. If a router has a static entry defined by the...

Configuring HDLC

HDLC is the default frame encapsulation on all serial interfaces. Therefore, its configuration can be a simple three-step process Step 1. Configure the encapsulation from the interface mode by using the encapsulation hdlc command. Step 2. Configure the DCE side of the link by using the clock rate clock_speed command. This is used only in routers that are attached with back-to-back cables. When using CSU DSUs, the CSU is the DCE device. Step 3. (Optional) Configure compression on both ends of...

Configuring IRB

Configuring IRB is a three-step process. The steps are as follows Step 1. Configure transparent bridging on the interfaces that you want to bridge and route. Use the process defined earlier. Recall that this consists of creating a bridge group and assigning interfaces to that group. Step 2. Configure IRB and the BVI. Assign the same bridge number to the BVI interface. For example if you use bridge 2, the BVI will be interface bvi 2. To enable IRB, use the following syntax from the router global...

Configuring Microsoft Windows 9598 Networking

The goal of all internetworking is to reliably transfer data from one network to another. Therefore, no model could be called reliable if it were not properly tested with real data and real applications. Therefore, the last components needed to completely model the internetwork are test data and test applications. As previously mentioned, the entire Microsoft Windows OS line, Windows 95 98 2000 and NT, provides all the network protocols needed to test many network models. The two protocols that...

Configuring NAT Dynamic Translation

Using the four-step process listed, now you will walk through the NAT configuration that you did earlier in this chapter. Figure 15-2 illustrates a private IP network of 172.16.1.0 24. This network needs reachability to the Internet specifically, the host 128.100.1.10 on the UW Ethernet segment. The router nat_router has a T1 connection to the Internet through the isp_router. The ISP has assigned the network 128.100.100.0 24 to nat_router for access to the Internet. The engineers who support...

Configuring NAT Static Translation

Configuring static translation is similar to configuring dynamic translation, except that you do not configure an IP pool. Instead, you configure a one-to-one address map of which specific hosts are to be translated to a specific address. A static translation can be used as an inside static translation or can have an outside static translation. Most implementations of NAT simply use an inside static translation, but when NAT is overlapping, you might want to use an outside source translation....

Configuring OSPF Stub Areas

Three types of OSPF stub areas must be configured To configure stub areas, use the area command followed by what type of stub area you want to configure. All routers on the same IP network must be in the same area, and area parameters also must match for neighbors and adjacencies to form. To configure Area X as a stub area, enter the following To configure Area X as a not-so-stubby area, enter the following Router(config-route)area X nssa default-information originate . Use the keyword...

Configuring Ppp Lapb and LQM

PPP link quality can be enforced or enabled on Cisco routers in two ways. One method is done by enabling LAPB numbered mode negotiation. This is done with the ppp reliable-link command. Another method is by enforcing Link Quality Monitoring (LQM) on the link with the ppp quality command. LQM monitors the link quality if the quality drops below a configured percentage, the router shuts down the link. The percentages are calculated for both incoming and outgoing traffic. The LQM out is calculated...

Configuring PPP Multilink

PPP multilink is a mechanism for combining, or bundling, multiple physical links into one large logical link. The logical end-to-end connection is called a bundle. This bundle provides increased bandwidth to the destination, along with reduced latency by allowing packets to be disassembled and sent down different links simultaneously to the same destination. The most common use of PPP multilink is with ISDN, which can use PPP multilink to bind two 64-kbps B channels together to form a single...

Configuring PPP on Asynchronous Ports for Analog Dial Links

Configuring PPP on asynchronous interfaces for analog dial connections can be more involved than configuring PPP on serial links. This section briefly lists the steps needed to configure PPP and then goes into greater detail on the more complex steps. The steps to configure PPP for use on an asynchronous dialup connection are as follows Step 1. Configure the modem and asynchronous port. Step 1 involves attaching and configuring the modem, and configuring the asynchronous port of the router....

Configuring PPP on Synchronous Serial Links

To configure PPP on a serial interface, you must first enable PPP encapsulation on the interface with the encapsulation ppp command. If you are configuring both ends of the PPP link, you need to configure PPP encapsulation on each side. If you are configuring a PPP link with two routers, using DTE-to-DCE cable connections, you also need to use the clock rate bps command on the DCE side of the connection. Essentially, setting the encapsulation coupled with a network layer address is all that is...

Configuring RFC 2225 Classical IP

Classical IP, specified in RFC 2225, is a dynamic method of IP interconnectivity through the ATM network. Classical IP uses RFC 2684 encapsulation. It provides a dynamic method for IP interconnectivity through the ATM network, freeing you from the necessity of configuring manually intensive mapping statements. Here is my definition of Classical IP It internetworks IP only. It allows native behavior of IP through the ATM cloud. This implies that the IP ARP function of mapping IP addresses to the...

Configuring RFC 2684

The complete theory behind RFC 2684 is covered in Cisco ATM Solutions. Here, I want to remind you that RFC 2684 (formerly RFC 1483) is an encapsulation method of all routed or bridged protocols over ATM. My formula for RFC 2684 is as follows RFC 2684 is the multiprotocol encapsulation method. The encapsulation method of multiple protocols (Layer 3 or bridged) over a single VC is accomplished using LLC SNAP the encapsulation method of a single protocol over a single VC is done using mux. Both...

Configuring Source Route Bridging

Source-route bridging can be configured in three primary ways Remote source-route bridging (RSRB) Configuring Basic Local Source-Route Bridging Local SRB in its simplest form exists between two rings on a router. Figure 13-16 illustrates this type of configuration. Figure 13-16. Basic Local SRB Configuration Figure 13-16. Basic Local SRB Configuration To configure this type of SRB, follow this two-step process Step 1. Enable the use of the RIF, if required, with the router interface command...

Configuring the Simple Network Time Protocol SNTP

On smaller routers that do not > support NTP, such as the Cisco 100x series, the 80x series, and other lower-end routers, you can deploy SNTP. However, SNTP lacks some of the enhanced features of NTP It cannot be an NTP server, and it provides no authentication and statistics mechanisms. SNTP can be configured in two ways, much like NTP Configure the router to passively listen for SNTP broadcasts on a wire. Statically map SNTP to a specific server. If both methods are configured, the router...

Configuring Token Ring Switching on the Catalyst 3920

Many of the same concepts that are found in Ethernet switching apply directly to Token Ring switches. For example, VLANs, VTP domains, and management VLANs are all found on Token Ring switches. For that reason, we will not spend a lot of time redefining these terms and their application. Instead, we will focus primarily on switch configuration. The Catalyst 3920 does not have a standard command-line interface for configuration. Instead, the configuration is totally menu or panel-driven. The...

Configuring Transparent Bridging

Configuring transparent bridging is a simple three-step process Step 1. Assign a bridge group number and define the Spanning-Tree Protocol. This is accomplished with this global command Router(config) bridge-group 1-255 protocol ieee ibm dec Step 2. Assign each network interface that is to be bridged to a bridge group by using the following interface command Router(config-if) bridge-group 1-255 If the interface is a Frame Relay multipoint interface, a frame-relay map statement will be needed to...

Configuring VLANs on the Catalyst 3920

The logical steps for configuring VLANs for Token Ring resemble the same steps that you use for configuring Ethernet VLANs. With Token Ring, however, you must define rings and bridges, which require a few extra steps. The steps for configuring VLANs on the Catalyst 3920 switch are as follows Step 1. Plan TrBRFs, TrCRFs, ring numbers, bridge numbers, and VLANs. Step 2. Configure VTP. Step 3. Configure TrBRF VLAN(s) and assign a bridge number to each TrBRF. Step 4. Configure TrCRFs VLANs and...

Control Examples

You must verify two things within the routing domains to allow IP end-to-end connectivity Notice that the IGRP domain is on a 24-bit boundary. This means that when the IGRP domain receives a route, it must exist on a major bit boundary or a 24-bit boundary for the interface to accept that route. Mutual redistribution must occur between EIGRP and IGRP, and EIGRP and OSPF. Beginning with the configuration for the canada_1 router, you can follow the three-step process for configuring EIGRP as...

Copyright

Contributing authors Daniel Keller (Chapter 7) 201 West 103rd Street Indianapolis, IN 46290 USA All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the publisher, except for the inclusion of brief quotations in a review. Printed in the United States of America 2 3 4 5 6 7 8 9 0 Library of Congress...

Credits

Michael Hakkert Tom Geitner William Warren San Dee Phillips Copy Editor Krista Hansing Technical Editors L.C. Broadnax Bill Kern Mike Reid John Tiso Sze Jee Wong Team Coordinator Tammi Ross Book Designer Gina Rexrode Cover Designer Louisa Klucznik Composition Octal Publishing, Inc. Indexer Tim Wright Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 http www.cisco.com Tel 408 526-4000 800 553-NETS (6387) Fax 408 526-4100 European Headquarters Cisco Systems...

D Spanning Tree Protocol STP

When Ethernet evolved from a single shared cable to networks with multiple bridges and hubs, a loop-detection and loop-prevention protocol was needed. The 802.1d protocol, developed by Radia Perlman, provided this loop protection. It did such a good job that when most networks went from bridged networks to routed networks, so the importance of Spanning Tree was almost forgotten. Because of this, Spanning Tree is probably the most used but least understood protocol in the modern internetwork....

Data Link Switching Plus DLSw

Data Link Switching (DLSw), as we know it today, was pioneered in 1995 by the Advanced Peer-to-Peer Networking (APPN) Implementers' Workshop (AIW), sponsored by IBM. It was not the first RFC on DLSw. IBM wanted to create a way to transport LLC2 frames across TCP IP networks and drafted RFC 1434 in 1993. The concept was sound, but it lacked (surprise) multivendor interoperability. The goal of the APPN AIW goal was to evolve the original DLSw RFC, RFC 1434, with new features. The original work...

Debug ip ospf adj and debug ip ospf events Commands

Two debug commands provide the Big D for OSPF debug ip ospf adj and debug ip ospf events. For the most part, the commands are identical. The output can be fairly heavy, so turn on logging if using this command in a production environment. This debug command is so comprehensive that it will alert you to a majority of common OSPF issues, such as the following Mismatched hello dead interval Mismatched authentication key Mismatched area IDs and area types

Default Administrative Distance

Enhanced Interior Gateway Routing Protocol (EIGRP) summary route External Border Gateway Protocol (BGP) Intermediate System-to-Intermediate System (IS-IS) A static route becomes floating when it is assigned a higher AD than that of the routing protocols. It is called floating because when a route known through some other means goes away, the floating static route floats to the top and is used by the router. For example, if you use the command ip route 10.1.1.0 255.255.255.0 BRI 0 200, you have...

Default Settings

Catalyst Switch Boot Register Bit Meanings and Default Table 1-7. Catalyst Switch Boot Register Bit Meanings and Default 0x1 Boot from onboard ROM, or boot to boot mode if a subset of the IOS exists. Causes the following (listed in order of precedence) Follow boot system commands found in the configuration. If a boot image in the BOOT environment variable list is not found, boot in ROM monitor mode. OEM bit 1 disabling the display of the Cisco banner on startup (Not used.) IP will...

Digital Voice Technology

Digital loop carrier technology was developed in the early 1970s with the idea of increasing transmission performance through digital technology. In addition to performance enhancements, digital technology is more reliable and easier to maintain than analog signaling. One of the key reasons for converting analog to digital is that digital signals are regenerated and do not accumulate noise in the same manner that analog signals do. Whereas analog signaling is represented as a continuous...

Displaying Access Lists

By now, you might want to display or troubleshoot your access lists. To view the access lists, use the following commands from the enable prompt show access-list Displays access lists from all protocols. This command displays the number of packets that pass each line of an access list. Use the clear access-list counter command to clear these counters. show ip access-list access-list number Displays all IP access lists defined. If you select a specific access list for display, only that list...

DLSw Advanced Configuration

DLSw provides many features that allow for easier peer configuration, explorer control, and backup and filtering capabilities. This section covers configuration of some of the more advanced features of DLSw+. These features include the following DLSw+ promiscuous peers configurations DLSw+ backup configurations DLSw+ border peers, peer groups, and demand peers Controlling DLSw explorers with ring lists, bridge group lists, and port lists Configuring DLSw+ reachability with the icanreach command...

DLSw Backup Configurations

DLSw offers a couple of methods to configure redundancy, depending on whether you want to keep the DLSw peer active. One method is configuring a peer as a backup peer. When a peer is configured as backup, it becomes active only when the router loses connectivity to the primary peer or DLSw router. The other method is used primarily to provide peer stability during a link failure. In this method, you tweak DLSw timeout and keepalives, to essentially keep the peer up during a routing protocol...

DLSw Backup over DDR

The other method of DLSw+ backup involves keeping the peer connection established during a link failure. For example, if you are using an ISDN link for backup, you might want to keep the peer active while the ISDN line dials and makes a connection. The time for link such as this to converge can exceed the DLSw+ keepalive timers and force the peer down. The DLSw+ keepalives operate on TCP port 2065, which also makes it hard to control significant traffic with ACLs because data and keepalives use...

DLSw Backup Peers

Backup peers are created by simply adding the backup-peer argument to the new remote peer. Before creating a backup peer, you must define the primary peer. The backup peer must point at a different DLSw router than the primary peer. The linger keyword tells the router not to disconnect the backup peer until the primary has been up for X amount of seconds. Without the linger keyword, the primary peer immediately becomes active when connectivity is restored. LLC2 sessions automatically are...

DLSw Border Peers Peer Groups and Demand Peers

Border peers and peer groups provide an effective way to scale DLSw networks that require any-to-any reachability and to control explorers. A DLSw router that requires any-to-any reachability would need a remote-peer statement to every router that it has a connection to. For example, Figure 13-37 illustrates a common network. Figure 13-37. DLSw Full Reachability Figure 13-37. DLSw Full Reachability Only two workstations are illustrated in the figure, but they represent workstations that would...

DLSw Capabilities Exchange

A key process that occurs during DLSw circuit establishment is the capabilities exchange. The capabilities exchange the process that differentiates DLSw from other bridging technologies. The exchange is a special DLSw SSP control message that describes the capabilities of the sending DLSw router. The initial capabilities exchange is always the first SSP message sent when a new connection between two DLSw devices occur. It is used to identify the DLSw version and other options that the DLSw...

DLSw Circuit Establishment

Circuit establishment occurs between two end systems. SNA circuit establishment occurs when a SNA TEST or XID explorer frame with a specific MAC address is generated from an end station. The DLSw router sends a CANUREACH frame to each active peer. The correct peer responds with an ICANREACH frame. After a series of XIDs and other information is exchanged, a circuit is established. Each circuit has a unique ID that allows a TCP peer connection to support multiple circuits. The ID is composed of...

DLSw Features

In 1991, RSRB was the only option that many network engineers had to bridge their Token Ring or LLC2 networks over an IP-based network. In a short time, thousands of RSRB networks were springing up. Soon, however, RSRB networks were sidelined by the newer way to transport LLC2 over an IP network, DLSw. By 1995, all future work on RSRB glided to a halt because the industry clearly was embracing DLSw. Since then, it has surfaced to become the most dynamic and one of the most reliable ways to...

DLSw Technical Overview

IEEE 802.2 LLC Type 2 was designed under the assumption that network transit delay would be small and predictable. After all, Token Ring and Ethernet are LAN protocols. When remote bridging is used over vast geographical distances, the network delay can vary drastically with the load on the link. When the delay becomes too large, LLC2 timeouts occur and retransmissions start happening. Because the frame is only delayed, LLC2 can become confused when it starts to see duplicate frames, and it...

Dynamic Access Lists

A dynamic access list is an access list that allows temporary access after a user has authenticated with the router. For example, in the field, you might want a Cisco engineer from the TAC to help you troubleshoot your network by logging into the routers. A dynamic access list could be created giving Cisco complete privileges for a predetermined amount of time. After a configured time limit expires, the session is closed and traffic is again denied. This form of access list is also referred to...

Eia530

Figure D-1 shows the EIA-530 serial cable assembly, and Table D-3 lists the pinouts. Figure D-1. EIA-530 Serial Cable Assembly Table D-3. EIA-530 DTE Cable Pinout (DB-60 to DB-25) Any pin not referenced is not connected. 2 The EIA-530 interface cannot be operated in DCE mode. A DCE cable is not available for the EIA-530 interface.

EIGRP Autosummarization

By default, EIGRP performs autosummarization in two situations Autosummarization will occur at the major class boundary during redistribution from EIGRP into a classful routing protocol, such as IGRP or RIP. This type of summarization cannot be disabled. Autosummarization will occur at the major class boundary when the route is advertised out an interface that is on a different major class boundary. This summarization can be disabled with the command no auto-summary from the...

EIGRP Equal and Unequal Cost Load Balancing

By default, EIGRP load-shares over four equal-cost paths. For load sharing to happen, the routes to load-share over must show up in the IP forwarding table or with the show ip route command. Only when a route shows up in the forwarding table with multiple paths to it will load sharing occur. Use the bandwidth interface command on serial links to ensure that EIGRP has a consistent perspective of the metrics of the network. This also might aid in making the route show up in the IP forwarding...

EIGRP Redistribution and Route Control

To filter routing updates in EIGRP, use a distribute list. A distribute list calls a standard or extended access list and filters routing updates accordingly. When redistributing one protocol into another, use the redistribute command along with a default metric. A route map should be used in place of a distribute list when controlling specific routes during the redistribution process. Redistribution happens automatically between IGRP and EIGRP when they are in the same autonomous systems....

EIGRP Stub Routing

In Cisco IOS Software Release 12.0(7)T, Cisco introduced EIGRP stub routing to further control stability and reduce resource utilization. This feature was fully integrated into Release 12.0(15)S. EIGRP stub routing functions very much like that of an OSPF stub area. The stub router has one exit path from the routing domain and forwards all traffic to a central or distribution router. Another way to say this is that the stub network cannot be a transit router for EIGRP, and it can have only one...

EIGRP Summarization

Understanding EIGRP summarization and knowing how to effectively use it are absolutely vital to the design of large EIGRP networks. EIGRP scales very well, but when the number of routes starts to climb into the hundreds, extra care should be taken to control route propagation and the query range. As much as EIGRP is plug-and-play on small networks, it is not on large networks. The larger the network is, the more care should be taken to control how routes propagation. Summarization provides two...

Equipment List

One Frame Relay switch four serial ports One access server backbone router eight asynchronous interfaces, one Ethernet port Two lab routers one Ethernet, two serial interfaces Three lab routers one Token Ring, two serial interfaces One lab router two Ethernet ports, one Token Ring port Three Ethernet hubs, four Token Ring hubs MAUs The hubs and MAUs may be substituted for a Catalyst 5000 with the appropriate number of ports. This lab is designed to be performed without any Catalyst switches....

Equipment Needed

Four Cisco routers with Ethernet interfaces. Two routers must have 100-Mbps interfaces. Recall that you need a minimum of a 100 Mbps to run any VLAN trunking protocol. If you do not have routers with 100-Mbps interfaces, routing also can be accomplished by configuring three Ethernet interfaces to the switch from a single router one interface would be in each VLAN. Three Cisco Catalyst Ethernet switches. This lab was designed specifically for two Catalyst 2900 3500 series switches and one...

Ethernet A Brief History of an Evolutionary Protocol

Its conception occurred at the Xerox Palo Alto Research Center (PARC), developed by Bob Metcalfe in 1972. In 1979, Digital Equipment Corp., Intel, and Xerox standardized the DIX V1.0 frame two years later, they refined it with the Version 2.0 frame. In 1981, the Institute of Electrical and Electronic Engineers (IEEE) project 802 decided to form the 802.3 subcommittee, which is almost synonymous with the Ethernet that we know today. Table 2-1 provides a great...

Ethernet CSMACD

Ethernet technology commonly is referred to as carrier-sense multiple access collision detect (CSMA CD). Ethernet transmits frames in the following manner 1. Carrier sense This also is known as listen before talking. An Ethernet station wanting to transmit a frame listens to the medium before it transmits to ensure that the medium is available. 2. Talk if quiet If the channel is quiet for a specific amount of time, the interframe gap (IFG) before the station might begin a transmission. If the...

Ethernet Operation

Ethernet operates at the OSI Layer 2, the data link layer. The data link layer actually is divided into two sublayers the MAC layer and the Logical Link Control (LLC) layer. The LLC layer 802.2, in this case is a standardized interface between a hardware-specific MAC and a Layer 3 protocol. The MAC layer has the following responsibilities Generating the physical source and destination address for a frame. These are 48-bit industry-wide unique addresses the first 3 bytes are assigned by the...

Ethernet Technical Overview

Ethernet is extremely popular, and many fine books and whitepapers have been written on it. For these reasons, we assume that you have some background in Ethernet technology therefore, this chapter does not cover Ethernet frames, hubs, and cables in any great length. You should become familiar with the different Ethernet frame types, DIX Version II, and 802.2 frames, as well as the different media types used in Ethernet. This chapter instead focuses more on Spanning Tree, Fast Ethernet, Gigabit...

Example 102 Output of the show ip protocols Command

Routing Protocol is igrp 2001' Sending updates every 90 seconds, next due in 19 seconds Invalid after 270 seconds, hold down 280, flushed after 630 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Default networks flagged in outgoing updates Default networks accepted from incoming updates IGRP metric weight K1 1, K2 0, K3 1, K4 0, K5 0 IGRP maximum hopcount 100 IGRP maximum metric variance 1 Redistributing igrp 2001 Routing for Networks...

Example 103 show ip route Command Output

Codes C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route, o - ODR Gateway of last resort is 172.18.1.5 to network 206.191.241.0 I* 206.191.241.0 24 100 1200 via 172.18.1.5, 00 00 52, EthernetO I...

Example 104 debug ip igrp transactions Command Output

Received update from 206.191.241.42 on Ethernet0 network 172.16.0.0, metric 1121211 (neighbor 1121111) sending update to 255.255.255.255 via Ethernet0 ( sending update to 255.255.255.255 via Ethernet1 ( sending update to 255.255.255.255 via Ethernet3 ( sending update to 255.255.255.255 via Ethernet5 (

Example 113 Verifying Flash and DRAM Memory with the show version and show flash Commands

Cisco Internetwork Operating System Software IOS (tm) 3000 Software (IGS-INR-L), Version 10.3(7), RELEASE SOFTWARE (fc1) Copyright (c) 1986-1995 by cisco Systems, Inc. Compiled Wed 01-Nov-95 12 40 by vatran Image text-base 0x03022C14, data-base 0x00001000 ROM System Bootstrap, Version 5.2(8a), RELEASE SOFTWARE ROM 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (f c1) skynet_access_1 uptime is 1 week, 2 days, 16 hours, 19 minutes System restarted by reload System image...

Example 114 Upgrading the IOS Through the TFTP Server

Sending 5, 100-byte ICMP Echos to 206.191.241.45, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 1 3 4 ms skynet_access_1 copy tftp flash This process will accept the copy options and then terminate the current system image to use the ROM based image for the copy. Routing functionality will not be available during that time. If you are logged in via telnet, this connection will terminate. Users with console access can see the results of the copy operation. There...

Example 1145 Eigrp Configuration of All Routers to This Point

Router eigrp 2001 network 172.16.0.0 At this time, you can verify routing by performing source pings and examining the route table. When basic routing is working, you can proceed to the next portion of the lab, which requires that barneys not propagate the subnet 172.16.3.0 throughout the EIGRP domain. There are many ways to accomplish this, but for this lab, you will use a distribution list. The list will be applied to EIGRP updates leaving the s0.1 and s0.2 interfaces on the barneys router....

Example 1146 Configuration of a Distribution List

Barneys(config) access-list 10 deny 172.16.3.0 0.0.0.255 barneys(config) access-list 10 permit any 10 out serial 0.1 barneys(config-router) distribute-list 10 out serial 0.2 By observing the forwarding table on g_and_s in Example 11-47, you can see that the route 172.16.3.0 24 is now missing. You still can ping the 172.16.20.0 24 subnet, so you know that the filter was a success.

Example 1147 Testing a Route Filter

Codes C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route 172.16.0.0 16 is variably subnetted, 7 subnets, 3 masks C 172.16.128.8...

Example 1148 Configuring a Default Route for EIGRP

Solar_bucks(config) ip route 0.0.0.0 0.0.0.0 172.16.50.1 solar_bucks(config) router eigrp 2001 solar_bucks(config-router) redistribute static 1544 100 254 1 1500 solar_bucks(config-router) Az solar_bucks By viewing the route or forwarding table on g_and_s or barneys, you can see that the default route is being propagated and is marked as an external, default candidate route, as shown in Example 11-49. Example 11-49 Viewing the Default Route on Barneys Codes C - connected, S - static, I - IGRP,...

Example 115 Identifying Line Entries of a Router the show line Command

Table 1-12 explains the line numbers and the numbering schemes found in Example 1-15. Table 1-12. Line Types and Number Schemes Table 1-12. Line Types and Number Schemes RS-232 DTE port used as a backup async port (TTY). asynchronous interface. Used typically for remote-node dial-in sessions that use protocols such as SLIP, PPP, and Xremote. Used for incoming Telnet, LAT, X.25 PAD, and protocol translation connections onto synchronous ports. Last TTY line number plus 2, through the maximum...

Example 1151 Final Router Configurations for the Internet Coffee Shop Network

< < < text omitted> > > interface EthernetO ip address 172.16.50.5 255.255.255.0 no ip directed-broadcast interface SerialO no ip address no ip directed-broadcast encapsulation frame-relay no ip mroute-cache frame-relay lmi-type cisco interface Serial0.1 point-to-point bandwidth 64 ip address 172.16.128.1 255.255.255.252 no ip directed-broadcast interface Serial0.2 point-to-point ip address 172.16.128.5 255.255.255.252 no ip directed-broadcast frame-relay interface-dlci 111 < <...

Example 116 Configuration of a Reverse Telnet Session

Enter configuration commands, one per line. End with CNTL Z. Router(config) ip host r1 2001 201.201.1.1 Router(config-line) transport input all Router(config-line) no exec Router(config-line) Az Router Example 1-16 also makes use of the no exec command entered under the line. This is optional in a reverse Telnet configuration. Adding this command lessens the likelihood of contention over the asynchronous port. An executive process, or exec, exists on all lines. These two process buffer data to...