Operation mode
Cisco iOS offers several different command-mode modes, each of which provides a set of related commands, different operational permissions, and operational functions.
Commands and functions in iOS environment:
User mode |
prompt |
User Rights |
How to enter |
Normal User mode
|
Router>
|
Normal user command
|
Automatic access to the power
|
Privileged User mode
|
router#
|
Management of the system
|
Router>enable
|
VLAN configuration mode
|
Router (VLAN) #
|
VLAN and VTP Management
|
Router#vlan data
|
Configuration mode
|
Router (config) #
|
System for Configuration
|
Router#config T
|
Configuration of common interfaces
Configuring virtual interfaces
Router (config) #interface loopback0
Configuring the Serial0 Interface
Router (config-if) #interface S0
Configuring the Ethernet0 Interface
Router (config-if) #interface E0
Configuring the Fa0 Interface
Router (config-if) #interface Fa0
Configuring the Atm0 Interface
Router (config-if) #interface Atm0
Configuring Port IP Addresses
Router (config-if) #ip address Port IP Mask
Ip
Routing configuration Command 1. Static routing
Router (config) #ip Route IP address of the next hop router in the destination network address mask
2. Default route
Router (config) #ip Route 0.0.0.0 0.0.0.0 The IP address of the next hop router
Quarantine commands for basic routers
Show version
Show processes
Show Protocols
Show Mem
Show IP route
Show Startup-config
Show Running-config
Show Flash
Show interfaces
Check the connectivity of the network
Ping Host name/IP address
Trace Host name/IP address
Traffic feature Check command
You can often use this command to discover unusual traffic to discover virus machines and IP addresses.
Show ip Cahce Flow
Security maintenance of system maintenance system
In addition to the network security system maintenance, network system equipment itself security maintenance is also very important.
Set Remote login Password
This password is used for network administrator remote Telnet logon into user mode, and remote administrators cannot log on if this password is not set.
R2621>enable!! Enter Privileged mode
R2621#configure Terminal!! Enter Global configuration mode
R2621 (config) #line vty 0 4!! Start configuring Telnet
R2621 (config-line) #password Cisco!! Set the password for Telnet
R2621 (config-line) #login!! Enable this password
Set Local
Console port Password This password is used by the local network administrator to enter user mode from the console port, and if the password is not set, the user can enter user mode directly.
R2621>enable!! Enter Privileged mode
R2621#configure Terminal!! Enter Global configuration mode
R2621 (config) #line con 0!! Start Configuring console
R2621 (config-line) #password Cisco!! Set Password for console
R2621 (config-line) #login!! Enable this password
Set the password for privileged mode the
The password is used for network administrators to enter privileged mode from normal user mode.
R2621>enable!! Enter Privileged mode
R2621#configure Terminal!! Enter Global configuration mode
R2621 (config) #enable secret Cisco!! will enable password The password is stored after encryption
Recover lost Password
Cisco router is one of the widely used computer network communication devices. In daily operation, the router plays an important role in the whole system, and it is unavoidable to operate it frequently. For example: Modify router configuration files, diagnose network failures, and so on. Once the password is forgotten, it can cause great trouble to the job, at this point, how to recover the password becomes particularly important.
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Note You cannot recover the encrypted password because the password is not visible. You must remove the original configuration and set a new password.
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Follow the process below to recover the password (enable password):
Step 1 connects the ASCII terminal or PC running the terminal emulator to the console port on the front panel of the router.
Step 2 to reboot the router. If you see the following prompts, enter N:
Would to enter the initial dialog? [Yes]: n
You then enter the normal operating state of the router.
Step 3 seconds after you see the user command prompt, EXEC prompt (router>). Enter the show version command to display the current configuration register value and record its configuration.
Step 4 If the interrupt function is turned on, type the break key to display the ROM monitor prompt (Rommon >). Go directly to step 6.
Step 5 I if the interrupt function is not turned on, or you cannot determine if it is turned on, turn off the router, wait 5 seconds, and then restart the router. In the first 5 seconds of the router startup, type the break key. The terminal displays the ROM monitor prompt (Rommon >).
Step 6 enters Confreg at the ROM monitor prompt, which allows you to configure register values.
Rommon> Confreg
Step 7 Enter Y in the following prompt state:
Do your wish to change the configuration? y/n [n]: Y
Step 8 always enter n for all prompts until you encounter the following prompts, and then enter Y:
Enable "Ignore system config Info"? [y/n] N:y
Step 9 always enter n for all prompts until you encounter the following prompts, and then enter Y:
Change the boot characteristics? [y/n] [n]: Y
Step 10 at the prompt below, type 2 and press ENTER. Configuration status will be displayed.
Enter to Boot:2
Step 11 Enter N at the following prompt:
Do your wish to change the configuration? y/n [n]: N
Step 12 enters reset at the ROM monitor prompt and the router resets.
rommon> Reset
Step 13 Enter n at the following prompt:
Would to enter the initial dialog? [Yes]: no
Step 14 Enter enable to enter privileged Command mode privileged EXEC mode:
Router> Enable
Password:
router#
Configuration can be changed only in enable mode. The prompt becomes privileged command mode prompt privileged EXEC prompt (router#):
Step 15 Enter the show Startup-config command to display the enable password in the configuration file:
router# Show Startup-config
Step 16 Enter the Configure Terminal command to enter configuration mode:
router# Configure terminal
Step 17 Enter the Configure register command to restore the original register value.
Step 18 Press Ctrl-z to exit configuration mode.
Step 19 Reboot the router and enter the password for recovery.
Ios
Version upgrades regularly upgrade iOS is important for device security, and here's a quick overview of how to upgrade iOS.
iOS version upgrade common commands
Router#dir all! Displays the version number of iOS on Flash
Router#copy Flash TFTP! Backup iOS system files to TFTP Server
Router#copy TFTP flash! Update system files on flash from TFTP server
Router#delete: File name! delete system files on Flash
Router#reload, Reboot!