Cisco IOS

1. What is router IOS[Internetwork Operating System]? a. It is responsible for management of hardware interfaces, protocols, and security on Cisco devices.
2. How to access IOS? a. You can access IOS using i. Console port 1) Used when physically close to the device ii. Auxiliary port 1) Similar to console except that it allows modem command configuration. Modem command configuration can be used to access router via a modem. 2) Used when not close to device
3. How to connect to a router to a network? a. Serial port i. Used to connect to WAN Links b. AUI Port i. Used to connect to LAN Links
4. How to configure router? a. From console port b. Via modem using auxiliary port c. From virtual terminal i. Telnet/SSH d. From tftp or sftp server i. Trivial 1) UDP ii. Secure 1) TCP

Local
Remote

Program/File Location
Bootstrap ROM
IOS Flash memory
Config file Saved config NVRAM Running config RAM

Router Boot power
1. POST
2. ROM
3. Boot strap program
4. IOS from flash memory a. Into RAM
5. IOS loads router configuration into RAM from NVRAM

Copy of configuration file in NVRAM is known as "startup-config"
Copy of configuration file in RAM is known as "running-config"

Type of information displayed during the boot process
1. Bootstrap program version
2. ICS software version
3. Router platform
4. Number and types of interfaces
5. Size of the RAM, NVRAM, and flash memory a. Flash Memory[this is where you upgrade] b. NVRAM where

router >

Router modes
1. Setup mode a. Used to manually create initial router configuration b. Gets into this mode when it fails to locate valid config file during the boot process c. You can also get into setup mode by typing "setup" command in the privileged mode
2. User mode a. Designated by greater than[>] sign on the command prompt b. It is used to display basic system information i. IOS Version ii. History size