4 Modes to Connect and Configure a Cisco Router
Cisco IOS Command Summary--Four Modes to Access and Configure a Cisco Router
The 4 modes for accessing and configuring a Cisco router are :
User EXEC mode
Privileged EXEC mode
Global configuration mode
Interface configuration mode
The 4 modes for accessing and configuring a Cisco router are :
User EXEC mode
Privileged EXEC mode
Global configuration mode
Interface configuration mode
Each mode has a unique command set.
Purpose of each Mode
user EXEC mode is the basic startup mode . A router configuration session are generally started making use of terminal emulation programs like Kermit , HyperTerminal , or telnet .
privileged EXEC mode is the system administrator mode . At this mode configuration files are viewed , the router is rebooted , and operating preference can be altered .
global configuration mode is used to modify system-wide configuration parameters, such as routing tables and routing algorithms.
interface configuration mode is utilized to change system-wide configuration preference , for example routing tables and routing algorithms .
Ways to Change Modes
user Exec mode is accessed by initiating a terminal emulation program , like kermit or HyperTerminal , or by initiating a telnet session . The workstation has to physically be attached to the console port on the router by possibly a rollover cable ( kermit or HyperTerminal ) or it can be an Ethernet port by a typical patch cable ( telnet ) . Check Figure 1 for port areas .Usually a password is provided to set up the connection . The user Exec mode prompt carries the following appearance : RouterName>
privileged Exec mode is accessed from user Exec mode by typing in enable . A password has to be provided to completly set up the connection . The privileged Exec mode prompt holds the following appearance : RouterName#
global configuration mode is accessed from privileged Exec mode by typing in configure terminalor config t . Password is not needed . The global configuration mode prompt carries the followingappearance : RouterName ( config )#
interface configuration mode is accessed from global configuration mode by typing in interfaceInterfaceName , in which the InterfaceName is can be Ethernet0 , Serial0 , or Serial1 . Follow is its appearance : RouterName( config-if )#
user EXEC mode is the basic startup mode . A router configuration session are generally started making use of terminal emulation programs like Kermit , HyperTerminal , or telnet .
privileged EXEC mode is the system administrator mode . At this mode configuration files are viewed , the router is rebooted , and operating preference can be altered .
global configuration mode is used to modify system-wide configuration parameters, such as routing tables and routing algorithms.
interface configuration mode is utilized to change system-wide configuration preference , for example routing tables and routing algorithms .
Ways to Change Modes
user Exec mode is accessed by initiating a terminal emulation program , like kermit or HyperTerminal , or by initiating a telnet session . The workstation has to physically be attached to the console port on the router by possibly a rollover cable ( kermit or HyperTerminal ) or it can be an Ethernet port by a typical patch cable ( telnet ) . Check Figure 1 for port areas .Usually a password is provided to set up the connection . The user Exec mode prompt carries the following appearance : RouterName>
privileged Exec mode is accessed from user Exec mode by typing in enable . A password has to be provided to completly set up the connection . The privileged Exec mode prompt holds the following appearance : RouterName#
global configuration mode is accessed from privileged Exec mode by typing in configure terminalor config t . Password is not needed . The global configuration mode prompt carries the followingappearance : RouterName ( config )#
interface configuration mode is accessed from global configuration mode by typing in interfaceInterfaceName , in which the InterfaceName is can be Ethernet0 , Serial0 , or Serial1 . Follow is its appearance : RouterName( config-if )#
Exiting Modes
Alternatives to Exit Options
How to get Command Help
By Typing " ? "a complete list of commands for that particular mode will be displayed. Writing a portion of a command followed by a ? would reveal further details about that command .
Selected Privileged Exec Mode Commands
show running-config –shows latest router configuration for the router
show startup-config – shows the startup configuration for the router
reload - this will restart the router, delete running configuration and reload startup configuration
copy running-config startup-config - stores the recent configuration to NVRAM . The fresh configuration will be effective after rebooting the router
show ip route – shows the details of the routing table
clear ip route – removes all routing table entries
show interfaces – this will display information about all network interfaces\
Mostly Used Global Configuration Commands
ip routing – It activates IP forwarding
no ip routing – This command is used for disabling IP forwarding and deleting all the information about routing table
ip route-cache – This will enable route caching
no ip route-cache – Turns off route caching
ip route ipDestinationAddr subnetmask gw_address –Used to insert a static route to the routing table. where as gw_address is the IP address of the default gateway (next hop router)
ip route ipDestinationAddr subnetmask Interface – Same as above, but Interface is the network interface name
no ip route ipDestinationAddr subnetmask gw_address – Removes route table entry
no ip route ipDestinationAddr subnetmask Interface – Removes route table entry
Global Configuration Commands (Examples)
ip route 10.20.0.0 255.255.0.0 10.11.1.58 – It adds a route to the routing table for network 10.20.0.0 having a subnet mask 255.255.0.0. 10.11.1.58 is the default gateway (next hop router) address.
ip route 0.0.0.0 0.0.0.0 10.0.8.8 – It adds 10.0.8.8 as a default gateway
Selected Interface Configuration Mode Commands
no shutdown – it activates network interface
shutdown – it disables network interface
ip address IPaddress netmask – This command is used to Set the IP address as well as subnet mask for an interface
- To be able to exit interface configuration mode, type in exit . The system will be returned to global configuration mode .
- In order to exit global configuration mode, type exit. The system will be returned back to privileged Exec mode.
- To be able to exit global configuration mode, type disable. The system will be returned to user Exec mode.
- In order to leave user Exec mode, type logout. This will end the session.
Alternatives to Exit Options
- In an effort to get back to privileged Exec mode immediately from any configuration mode, type in END.
- You can also exit by typing in logout or exit from privileged Exec mode
How to get Command Help
By Typing " ? "a complete list of commands for that particular mode will be displayed. Writing a portion of a command followed by a ? would reveal further details about that command .
Selected Privileged Exec Mode Commands
show running-config –shows latest router configuration for the router
show startup-config – shows the startup configuration for the router
reload - this will restart the router, delete running configuration and reload startup configuration
copy running-config startup-config - stores the recent configuration to NVRAM . The fresh configuration will be effective after rebooting the router
show ip route – shows the details of the routing table
clear ip route – removes all routing table entries
show interfaces – this will display information about all network interfaces\
Mostly Used Global Configuration Commands
ip routing – It activates IP forwarding
no ip routing – This command is used for disabling IP forwarding and deleting all the information about routing table
ip route-cache – This will enable route caching
no ip route-cache – Turns off route caching
ip route ipDestinationAddr subnetmask gw_address –Used to insert a static route to the routing table. where as gw_address is the IP address of the default gateway (next hop router)
ip route ipDestinationAddr subnetmask Interface – Same as above, but Interface is the network interface name
no ip route ipDestinationAddr subnetmask gw_address – Removes route table entry
no ip route ipDestinationAddr subnetmask Interface – Removes route table entry
Global Configuration Commands (Examples)
ip route 10.20.0.0 255.255.0.0 10.11.1.58 – It adds a route to the routing table for network 10.20.0.0 having a subnet mask 255.255.0.0. 10.11.1.58 is the default gateway (next hop router) address.
ip route 0.0.0.0 0.0.0.0 10.0.8.8 – It adds 10.0.8.8 as a default gateway
Selected Interface Configuration Mode Commands
no shutdown – it activates network interface
shutdown – it disables network interface
ip address IPaddress netmask – This command is used to Set the IP address as well as subnet mask for an interface