First, the router boot initial sequence
When the router is initialized, the router performs the following:
1) Self-power self-test from the ROM, detect the basic operation of the CPU, memory, and interface circuit.
2) Boots from ROM to download the operating system to the main memory.
3) Guide the operating system by the boot predetermined by the configuration register, the configuration file is used by Flash or network.
The boot system command determines its exact location.
4) The operating system downloads to the low address memory, and then determines the work hardware and software of the router after the operating system is determined.
Part of the section shows the results on the screen.
5) The configuration file stored in NVRAM is loaded to the main memory and configure the startup routing process.
Port address, set media characteristics. If you have a valid configuration file in NVRAM, enter the setup session model
formula.
6) Then enter the system configuration session, display configuration information, such as the configuration information of each interface.
Second, Setup session
When there is no valid profile in NVRAM, the router will automatically enter the setup session mode. In the future
Type Setup in the command line for configuration.
The setup command is an interactive command, each question has a default configuration, if you use default
The configuration is knocked back to the car. If the system has been configured, the current configuration value is displayed. If it is the first time
Configuration, the factory setting is displayed. When the screen is displayed "---- More ------", type the space button to continue;
If you exit from Setup, just type Ctrl-C.
1. SETUP main parameters:
Configure its general parameters, including:
Host name: hostname
Privilege Call: Enable Password
Virtual End Password: Virtual Terminal Password
SNMP network management: SNMP Network Management
IP: IP
IGRP Routing Agreement: IGRP Routing
RIP Routing Protocol: RIP Routing
Decnet: Decnet., Etc.
Where console's Secret, the PASSWORD setting:
Enable Secret
Enable Password
Virtual Terminor's PASSWORD setting:
Line Vty
Password
Host Name setting:
Hostname
2, setup interface parameters:
Set interface parameters, such as Ethernet ports, Tokenring ports, synchronization ports, asynchronous ports, etc. Including IP address, child
Web screen shielding, Tokengring rate, etc.
3, setup description:
After the above parameters are set, the command prompts whether to use the above configuration, if the answer is "yes", the system
Will store the above configuration parameters, the system can be used.
4, setup related commands:
SHOW Config
Write Memory
Write Erase
Reload
Setup
5, router lost Password recovery
The following measures can be recovered:
Enable Secret Password (suitable for 10.3 (2) or updated version)
Enable Password
Console Password
By modifying the Configuration Register (factory 0x2102), the router ignores Password, this
You can enter the router, you can see Enable Password and Console Password, but ENA
Ble Secret Password is encrypted and can only replace it. Configuration registe you can enter
The R value is 0x142.
· Run Password recovery may cause the system down to drop an hour and a half;
· Console Terinal is connected to the console port of the router, the confirmation terminal is set to 9600bps, 8
Data Bit, NO Parity, 1 Stop bit;
· Show version displays the Configuration Register 0x2102;
· Press "Ctrl Break", enter the ROM Monitor status, prompt ">";
· Type "> O / R 0x142", modify the Configuration Register to 0x142, you can ignore the original
Password;
· Type "> Initialize", initialize the router, wait for some time, the router will appear below
:
System Configuration Diaglog ... "
ENTER "NO"
Tip "Press Return TO GET STARTED!", Press "Enter"
· Enter privileged model
Router> enable
Router # SHOW Startup-Config
This will get PASSWORD (Enable & Console Password)
· Modify Password
"Router # config ter"
"Router (config) # Enable Secret Cisco
"Router # enable password cisco1"
"Router (config) # line con 0
"Router # Password Cisco"
"Router (config) # config-register 0x2102
"Ctrl Z"
"Router # Copy Running-Config Startup-Config"
"reload"
· Enter privileged users with Password Cisco.
Third, router configuration
1) Router mode
In the Cisco router, the command interpreter is called EXEC, and EXEC explains the user typed command and performs the corresponding
Operation, you must log in to the router before entering the exec command. Based on security reasons, EXEC setup
Two access: user-level and privileged levels, user-level executable commands are subset of privileged commands.
In privileged level, you can use: Configuration, Interface, Subinterface, Line, Rout
Er, Router-Map and other orders.
2) Configuration mode
Use the config command to enter the configuration mode. After entering this mode, the exec prompts the user-available configuration.
As the terminal, NVRAM, the network is three, the default is a terminal mode.
3) IP routing protocol mode
Enter the router command in configuration mode to enter IP routing protocol mode, and optional routing protocols are generally
: BGP, EGP, IGRP, EIGRP, RIP, etc. dynamic routing and static routes.
4) Interface configuration mode
Many features can be set on each port, the interface configuration command modifies Ethernet, token ring network, FDDI
Or synchronous, asynchronous ports, etc.
5) Password configuration
You can use your password to limit access to the router, the password can be set to the specific line or privileged
XEC mode.
LINE Console 0 Command Settings Console Terminal Password LINE VTY 0 Command Settings Telnet Five End Password
Enable-password command sets privilege EXEC access
6) Router naming
Use hostname in configuration mode, such as:
Hostname Routera
Fourth, user help tips
1. Type it under the user prompt? You can list common commands, usually have the following command:
Connect opens a mid-end connection
Disconnect Close an existing Telnet session
Enable enters privileged level
EXIT Exit EXEC
HELP interaction help system description
LOCK terminal lock
Login login with a specific user
Logout Exit EXEC
Ping Send ECHO Information
Resume Reverts to an activated Telnet connection
Show displays system information that is running
SYSTAT displays system information that is running
Telnet opens a Telnet connection
TERMINAL sets terminal line parameters
Where lists the activated Telnet connection
2, up and down related help
Up and down related help include:
Symbol conversion: Type the command is prompted when there is a message;
Keyword completion: Type part of the command word;
Command memory: Available "" to call up the previous command;
Command prompt: When the command is not complete, use "?" Alternative
