There are 3 router modes available to cisco routers. These modes can be accessed via Command Line Interface or commonly known as CLI which is also known as EXEC. Therefore, 3 router modes is also the 3 exec modes which has its own different levels of access to Cisco IOS Commands.

1. User Exec Mode – This is also known as Privilege Level 1. By default configuration of router, this mode grants user to have access to some information about the router, viewing the status of the routing table as well as the status of the interfaces within. However, you cannot make any changes and or view the running configuration file. The prompt for this level is Router>, where Router is the name of the device.
2. User Privilege Mode – This mode is also known as Privilege Level 15. This level is somewhat similar to the administrator privilege in Windows operating systems and root in Linux. By typing enable in User Exec Mode, the user is taken into a higher privilege which is privilege 15 by default. This provides a high-level management access to the IOS, where User EXEC mode command can also be used. The prompt for this level is Router#, sending disable command will eventually set a lower privilege level of 1 which is the User Exec Mode.
3. Configuration Mode – This mode gives you total access to configuration commands that affect the entire system. There are several source of configuration commands like terminal, memory and network. User in Privilege Exec Mode can enter within configuration mode by switching to terminal using “configure terminal” command or “config term” as well as “conf t”. The prompt for this mode is Router(config)#, hitting Ctrl+Z enables user to go back to Privilege Exec Mode.

Command Example

System Bootstrap, Version 12.2(8r)YN, RELEASE SOFTWARE (fc1)

TAC Support: http://www.cisco.com/tac

Copyright (c) 2002 by Cisco Systems, Inc.

C800/SOHO series (Board ID: 28-130) platform with 65536 Kbytes of main memory

program load complete, entry point: 0×80013000, size: 0x6897e8

Self decompressing the image :##############################################[OK]

Cisco SOHO91 (MPC857DSL) processor (revision 0×300) with 5893kK/65536K bytes of memory.

Processor board ID AMB080903VX (1784032485), with hardware revision 0000

CPU rev number 7

2 Ethernet interfaces

128K bytes of NVRAM.

8192K bytes of processor board System flash (Read/Write)

2048K bytes of processor board Web flash (Read/Write)

Press RETURN to get started! <- hit enter

Router> <- this is the User Exec Mode

Router> enable <- type enable to enter Privilege Exec Mode level 15

Router# configure terminal <- configure terminal command lets to escalate to configuration mode

Router(config)# <- this prompt states that current configuration affects the terminal

Router(config)# Ctrl+Z <- hitting ctrl+z return you to Privilege Exec Mode

Router# <- by executing disable returns the prompt to User Exec Mode

Router>