Specifications
Table Of Contents
- Contents
- Preface
- Getting Started
- Basic Router Configuration
- Interface Port Labels
- Viewing the Default Configuration
- Information Needed for Configuration
- Configuring Basic Parameters
- Configuring Static Routes
- Configuring Dynamic Routes
- Configuring Enhanced IGRP
- Basic Router Configuration
- Configuring Your Router for Ethernet and DSL Access
- Sample Network Deployments
- Configuring PPP over Ethernet with NAT
- Configuring PPP over ATM with NAT
- Configuring a LAN with DHCP and VLANs
- Configuring a VPN Using Easy VPN and an IPSec Tunnel
- Configure the IKE Policy
- Configure Group Policy Information
- Apply Mode Configuration to the Crypto Map
- Enable Policy Lookup
- Configure IPSec Transforms and Protocols
- Configure the IPSec Crypto Method and Parameters
- Apply the Crypto Map to the Physical Interface
- Create an Easy VPN Remote Configuration
- Verifying Your Easy VPN Configuration
- Configuration Example
- Configuring VPNs Using an IPSec Tunnel and Generic Routing Encapsulation
- Configuring a Simple Firewall
- Configuring a Wireless LAN Connection
- Sample Configuration
- Configuring Additional Features and Troubleshooting
- Additional Configuration Options
- Configuring Security Features
- Configuring Dial Backup and Remote Management
- Troubleshooting
- Reference Information
- Cisco IOS Software Basic Skills
- Concepts
- ROM Monitor
- Common Port Assignments

A-2
Cisco 1800 Series Integrated Services Routers (Fixed) Software Configuration Guide
OL-6426-02
Appendix A Cisco IOS Software Basic Skills
Understanding Command Modes
You can use the terminal emulation software to change settings for the type of device that is connected
to the PC, in this case a router. Configure the software to the following standard VT-100 emulation
settings so that your PC can communicate with your router:
• 9600 baud
• 8 data bits
• No parity
• 1 stop bit
• No flow control
These settings should match the default settings of your router. To change the router baud, data bits,
parity, or stop bits settings, you must reconfigure parameters in the ROM monitor. For more information,
see
Appendix C, “ROM Monitor.” To change the router flow control setting, use the flowcontrol line
configuration command.
For information on how to enter global configuration mode so that you can configure your router, see
the
“Entering Global Configuration Mode” section later in this chapter.
Understanding Command Modes
This section describes the Cisco IOS command mode structure. Each command mode supports specific
Cisco IOS commands. For example, you can use the interface type number command only from global
configuration mode.
The following Cisco IOS command modes are hierarchical. When you begin a router session, you are in
user EXEC mode.
• User EXEC
• Privileged EXEC
• Global configuration
Table A-2 lists the command modes that are used in this guide, how to access each mode, the prompt
you see in that mode, and how to exit to a mode or enter the next mode. Because each mode configures
different router elements, you might need to enter and exit modes frequently. You can see a list of
available commands for a particular mode by entering a question mark (?) at the prompt. For a
description of each command, including syntax, see the Cisco IOS 12.3 documentation set.