Cisco Router 826 Routers Software Configuration Guide

							  
Contents
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Resetting the Password and Saving Your Changes5-14
Resetting the Configuration Register Value5-14
Managing the Cisco Router Web Setup Tool5-14
Pointers to CRWS Documentation5-15
APPENDIX ACisco IOS Basic SkillsA-1
Configuring the Router from a PCA-1
Understanding Command ModesA-2
Getting HelpA-4
Enable Secret and Enable PasswordsA-5
Entering Global Configuration ModeA-5
Using CommandsA-6
Abbreviating CommandsA-6
Undoing CommandsA-6
Command-Line Error MessagesA-6
Saving Configuration ChangesA-7
SummaryA-7
Where to Go NextA-8
APPENDIX BROM MonitorB-1
Entering the ROM MonitorB-1
ROM Monitor CommandsB-2
Command DescriptionsB-3
Disaster Recovery with TFTP DownloadB-3
TFTP Download Command VariablesB-4
Using the TFTP Download CommandB-5
Configuration RegisterB-6
Changing the Configuration Register ManuallyB-6
Changing the Configuration Register Using PromptsB-6
Console DownloadB-7
Command DescriptionB-8
Error ReportingB-8
Debug CommandsB-9
Exiting the ROM MonitorB-10
APPENDIX CCommon Port AssignmentsC-1
INDEX 
						

							  
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About This Guide
This preface discusses the audience, organization, and conventions used in this guide. It also provides 
information on how to access this guide and other Cisco documentation on the Documentation 
CD-ROM. 
This document provides software configuration information for the following Cisco routers:
•Cisco 826 router and Cisco SOHO 76 router
Cisco 827 router and Cisco SOHO 77 router
Cisco 828 router and Cisco SOHO 78 router
Cisco 831 router and Cisco SOHO 91 router
Cisco 836 router and Cisco SOHO 96 router
Cisco 837 router and Cisco SOHO 97 router
Audience
This guide is intended for network administrators whose backgrounds vary from having no or little 
experience configuring routers to having a high level of experience. You can use this guide in the 
following ways:
You have configured the software using the Cisco Router Web Setup tool, and want to configure 
additional advanced software features using the command-line interface (CLI).
You want to configure the software using only the CLI.
NoteCisco recommends that inexperienced network administrators use the Cisco Router Web Setup tool to 
configure their routers.
Refer to the “Organization” section of this preface to help you decide which chapter(s) contains the 
information you need to configure your software. 
						

							  
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About This Guide
Organization
Organization
This guide contains the following information:
Chapter 1, “Concepts”—Provides general concept explanations of features.
Chapter 2, “Network Scenarios”—Describes five Internet access scenarios and one voice scenario, 
each featuring the Cisco 827 router, with their specific network topologies and configurations.
Chapter 3, “Basic Router Configuration”—Explains basic router configuration, feature by feature. 
Chapter 4, “Advanced Router Configuration”—Explains advanced router configuration features.
Chapter 5, “Troubleshooting”—Provides information on identifying and solving problems with the 
ADSL line and the telephone interface. Also explains how to recover a lost software password.
Appendix A, “Cisco IOS Basic Skills”—Explains what you need to know about the Cisco IOS 
software before you begin to configure it.
Appendix B, “ROM Monitor”—Describes the use of the ROM Monitor (ROMMON) utility.
Appendix C, “Common Port Assignments”—Describes the currently assigned Transmission 
Control Protocol (TCP) and User Datagram Protocol (UDP) port numbers.
Conventions
This guide uses the following conventions for instructions and information.
Notes, Cautions, and Timesavers
Notes, cautions and time-saving tips use the following conventions and symbols.
NoteMeans reader take note. Notes contain helpful suggestions or references to materials not contained in 
this manual.
CautionThis caution symbol means reader be careful. In this situation, you might do something that could result 
in equipment damage or loss of data.
TimesaverThis symbol means the described action saves time.  
						

							  
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About This Guide
Related Documents
Command Conventions
Ta b l e 1 describes the command syntax used in this document.
Related Documents
The following publications provide related information on this product:
Cisco 826 and Cisco SOHO 76 routers:
–Cisco 826 and Cisco SOHO 76 Routers Hardware Installation Guide—Provides detailed 
instructions for installing Cisco 826 and Cisco SOHO 76 routers.
–Cisco 826 and Cisco SOHO 76 Router Cabling and Setup Quick Start Guide—Provides 
instructions for quickly cabling and powering up Cisco 828 and SOHO 78 routers.
Cisco 827 and Cisco SOHO 77 routers:
–Cisco 827 Routers Hardware Installation Guide—Provides detailed instructions for installing 
the Cisco 827 and Cisco SOHO 77 routers.
–Quick Start Guide - Installing Your Cisco 827 Routers—Provides instructions for quickly 
cabling and powering up Cisco 827 and Cisco SOHO 77 routers.
Cisco 828 and SOHO 78 routers:
–Cisco 828 Router and SOHO 78 Router Hardware Installation Guide—Provides detailed 
instructions for installing the Cisco 828 and SOHO 78 routers.
Cisco 831 and SOHO 91 routers:
–Cisco 831 Router and SOHO 91 Router Hardware Installation Guide—Provides detailed 
instructions for installing the Cisco 831 and Cisco SOHO 91 routers.
–Cisco 831 Router and SOHO 91 Router Cabling and Setup Quick Start Guide—Provides 
detailed instructions on quickly cabling and powering up Cisco 831 and SOHO 91 routers.
Table 1 Conventions
Convention Description
boldfaceCommands and keywords.
italicCommand input that is supplied by you.
[ ] Optional keywords and default responses to system 
prompts appear within square brackets.
{x|x|x} A choice of keywords (represented by x) appears in 
braces separated by vertical bars. You must select 
one.
^ or Ctrl Represent the key labeled Control. For example, 
when you read ^D or Ctrl-D, you should hold down 
the Control key while you press the D key.
screen fontExamples of information displayed on the screen.
boldface screen 
fontExamples of information that you must enter. 
						

							  
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Obtaining Documentation
Cisco 836 and Cisco SOHO 96 routers:
–Cisco 836 and SOHO 96 Cabling and Setup Quick Start Guide—Provides quick installation 
information on the Cisco 836 and Cisco SOHO 96 routers.
–Cisco 831 and SOHO 91 Hardware Installation Guide—Provides installation information on 
the Cisco 836 and Cisco SOHO 96 routers.
Cisco 837 and SOHO 97 routers:
–Cisco 837 Router and SOHO 97 Router Hardware Installation Guide—Provides detailed 
instructions for installing the Cisco 837 and Cisco SOHO 97 routers.
–Cisco 837 Router and SOHO 97 Router Cabling and Setup Quick Start Guide—Provides 
detailed instructions on quickly cabling and powering up Cisco 837 and SOHO 97 routers.
Cisco documentation and additional literature are available in a CD-ROM package, which ships with 
your product. The Documentation CD-ROM, a member of the Cisco Connection Family, is updated 
monthly. Therefore, it might be more current than printed documentation. To order additional copies of 
the Documentation CD-ROM, contact your local sales representative or call customer service. The 
CD-ROM package is available as a single package or as an annual subscription. You can also access 
Cisco documentation on the World Wide Web at http://www.cisco.com, http://www-china.cisco.com, or 
http://www-europe.cisco.com.
If you are reading Cisco product documentation on the World Wide Web, you can submit comments 
electronically. Click Feedback in the toolbar and select Documentation. After you complete the form, 
click Submit to send it to Cisco. We appreciate your comments.
Obtaining Documentation
Cisco provides several ways to obtain documentation, technical assistance, and other technical 
resources. These sections explain how to obtain technical information from Cisco Systems.
Cisco.com
You can access the most current Cisco documentation on the World Wide Web at this URL:
http://www.cisco.com/univercd/home/home.htm
You can access the Cisco website at this URL:
http://www.cisco.com
International Cisco web sites can be accessed from this URL:
http://www.cisco.com/public/countries_languages.shtml
Documentation CD-ROM
Cisco documentation and additional literature are available in a Cisco Documentation CD-ROM 
package, which may have shipped with your product. The Documentation CD-ROM is updated monthly 
and may be more current than printed documentation. The CD-ROM package is available as a single unit 
or through an annual subscription. 
						

							  
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Registered Cisco.com users can order the Documentation CD-ROM (product number 
DOC-CONDOCCD=) through the online Subscription Store:
http://www.cisco.com/go/subscription
Ordering Documentation
You can find instructions for ordering documentation at this URL:
http://www.cisco.com/univercd/cc/td/doc/es_inpck/pdi.htm
You can order Cisco documentation in these ways:
Registered Cisco.com users (Cisco direct customers) can order Cisco product documentation from 
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http://www.cisco.com/en/US/partner/ordering/index.shtml
Registered Cisco.com users can order the Documentation CD-ROM (Customer Order Number 
DOC-CONDOCCD=) through the online Subscription Store:
http://www.cisco.com/go/subscription
Nonregistered Cisco.com users can order documentation through a local account representative by 
calling Cisco Systems Corporate Headquarters (California, U.S.A.) at 408 526-7208 or, elsewhere 
in North America, by calling 800 553-NETS (6387). 
Documentation Feedback
You can submit comments electronically on Cisco.com. On the Cisco Documentation home page, click 
Feedback at the top of the page.
You can e-mail your comments to [email protected].
You can submit your comments by mail by using the response card behind the front cover of your 
document or by writing to the following address:
Cisco Systems
Attn: Customer Document Ordering
170 West Tasman Drive
San Jose, CA 95134-9883
We appreciate your comments.
Obtaining Technical Assistance
Cisco provides Cisco.com, which includes the Cisco Technical Assistance Center (TAC) Website, as a 
starting point for all technical assistance. Customers and partners can obtain online documentation, 
troubleshooting tips, and sample configurations from the Cisco TAC website. Cisco.com registered users 
have complete access to the technical support resources on the Cisco TAC website, including TAC tools 
and utilities.  
						

							  
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Cisco.com
Cisco.com offers a suite of interactive, networked services that let you access Cisco information, 
networking solutions, services, programs, and resources at any time, from anywhere in the world. 
Cisco.com provides a broad range of features and services to help you with these tasks:
Streamline business processes and improve productivity 
Resolve technical issues with online support
Download and test software packages
Order Cisco learning materials and merchandise
Register for online skill assessment, training, and certification programs
To obtain customized information and service, you can self-register on Cisco.com at this URL:
http://www.cisco.com
Technical Assistance Center
The Cisco TAC is available to all customers who need technical assistance with a Cisco product, 
technology, or solution. Two levels of support are available: the Cisco TAC website and the Cisco TAC 
Escalation Center. The avenue of support that you choose depends on the priority of the problem and the 
conditions stated in service contracts, when applicable.
We categorize Cisco TAC inquiries according to urgency:
Priority level 4 (P4)—You need information or assistance concerning Cisco product capabilities, 
product installation, or basic product configuration.
Priority level 3 (P3)—Your network performance is degraded. Network functionality is noticeably 
impaired, but most business operations continue.
Priority level 2 (P2)—Your production network is severely degraded, affecting significant aspects 
of business operations. No workaround is available.
Priority level 1 (P1)—Your production network is down, and a critical impact to business operations 
will occur if service is not restored quickly. No workaround is available.
Cisco TAC Website
You can use the Cisco TAC website to resolve P3 and P4 issues yourself, saving both cost and time. The 
site provides around-the-clock access to online tools, knowledge bases, and software. To access the 
Cisco TAC website, go to this URL:
http://www.cisco.com/tac
All customers, partners, and resellers who have a valid Cisco service contract have complete access to 
the technical support resources on the Cisco TAC website. Some services on the Cisco TAC website 
require a Cisco.com login ID and password. If you have a valid service contract but do not have a login 
ID or password, go to this URL to register:
http://tools.cisco.com/RPF/register/register.do
If you are a Cisco.com registered user, and you cannot resolve your technical issues by using the Cisco 
TAC website, you can open a case online at this URL:
http://www.cisco.com/en/US/support/index.html 
						

							  
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If you have Internet access, we recommend that you open P3 and P4 cases through the Cisco TAC 
website so that you can describe the situation in your own words and attach any necessary files.
Cisco TAC Escalation Center
The Cisco TAC Escalation Center addresses priority level 1 or priority level 2 issues. These 
classifications are assigned when severe network degradation significantly impacts business operations. 
When you contact the TAC Escalation Center with a P1 or P2 problem, a Cisco TAC engineer 
automatically opens a case.
To obtain a directory of toll-free Cisco TAC telephone numbers for your country, go to this URL:
http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml
Before calling, please check with your network operations center to determine the level of Cisco support 
services to which your company is entitled: for example, SMARTnet, SMARTnet Onsite, or Network 
Supported Accounts (NSA). When you call the center, please have available your service agreement 
number and your product serial number.
Obtaining Additional Publications and Information
Information about Cisco products, technologies, and network solutions is available from various online 
and printed sources.
The Cisco Product Catalog describes the networking products offered by Cisco Systems as well as 
ordering and customer support services. Access the Cisco Product Catalog at this URL:
http://www.cisco.com/en/US/products/products_catalog_links_launch.html
Cisco Press publishes a wide range of networking publications. Cisco suggests these titles for new 
and experienced users: Internetworking Terms and Acronyms Dictionary, Internetworking 
Technology Handbook, Internetworking Troubleshooting Guide, and the Internetworking Design 
Guide. For current Cisco Press titles and other information, go to Cisco Press online at this URL:
http://www.ciscopress.com
Packet magazine is the Cisco monthly periodical that provides industry professionals with the latest 
information about the field of networking. You can access Packet magazine at this URL:
http://www.cisco.com/en/US/about/ac123/ac114/about_cisco_packet_magazine.html
iQ Magazine is the Cisco monthly periodical that provides business leaders and decision makers 
with the latest information about the networking industry. You can access iQ Magazine at this URL:
http://business.cisco.com/prod/tree.taf%3fasset_id=44699&public_view=true&kbns=1.html
Internet Protocol Journal is a quarterly journal published by Cisco Systems for engineering 
professionals involved in the design, development, and operation of public and private internets and 
intranets. You can access the Internet Protocol Journal at this URL:
http://www.cisco.com/en/US/about/ac123/ac147/about_cisco_the_internet_protocol_journal.html
Training—Cisco offers world-class networking training, with current offerings in network training 
listed at this URL:
http://www.cisco.com/en/US/learning/le31/learning_recommended_training_list.html 
						

							  
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