Configuring a Network Operating System

IOS Bootcamp

Sell	The user interface that allows users to request specific tasks from the computer
Kernel	Communicates between the hardware and software of a computer and manages how hardware are used
Hardware	The physical parts of the computer including

PURPOSE OF THE OPERATING SYSTEM
End Devices	Intermediary Devices
Use of a mouse	Configure interfaces
View output	Enable routing and switching functions
Enter Text
All networking devices come with a default IOS
Possible to upgrade IOS version or feature set
In this course, the primary focus is on Cisco IOS Release 15.x

Cisco INTERNETWORK OPERATING SYSTEM
_{Network infrastructure software used around the world integrate technology, business-critical services, and hardware support}
SOFTWARE VARIATIONS		PROPERTIES	FUNCTIONS
Cisco IOS XE	Enterprise	Unix like Operating System		Security
_{optimal for facilitating enterprise and service provider services}		Typically stored in Flash		Routing
Cisco IOS XR	Service Provider	copied from flash to volatile RAM		QoS
_{Self-healing, self-defending, always-on OS provides service providers a foundation for network and service convergence scaling up to 92Tbps}		Can be used to store multiple versions of IOS		Managing Resources
Cisco NX-OS	Nexus - Cloud	Image in compressed format (*.bin)		Addressing
_{This full-featured, modular, and scalable OS offers high availability, simplified operations, and exceptional flexibility}		Can be inserted like SDRAM or can be on-board		Interface

Console
- Device is accessible even if no networking services have been configured (out-of-band)
- Need a special console cable
- Allows configuration commands to be entered
- Should be configured with passwords to prevent unauthorized access
- Device should be located in a secure room so console port cannot be easily accessed
Telnet
- Method for remotely accessing the CLI over a network
- Require active networking services and one active interface that is configured
Secure Shell (SSH)
- Remote login similar to Telnet, but utilizes more security
- Stronger password authentication
- Uses encryption when transporting data
AUX
- Out-of-band connection
- Uses telephone line
- an be used like console port

HOT KEYS AND SHORTCUTS
Tab	Completes the remainder of a partially typed command or keyword
Ctrl-R	Redisplays a line
Ctrl-A	Moves to the beginning of the line
Ctrl-Z	Exits the configuration mode and returns to user EXEC
Down Arrow	Allows the user to scroll forward through former commands
Up Arrow	Allows the user to scroll backward through former commands
Ctrl-Shift-6	Allows the user to interrupt an IOS process such as ping or traceroute
Ctrl-C	Exits the current configuration or aborts the current command

GETTING BASIC

IOS Examination Commands

SECURING DEVICE ACCESS
IOS MODE	COMMAND	DESCRIPTION
(config)#	enable password	Limits access to the privileged EXEC mode
(config)#	enable secret	Encrypted, limits access to the privileged EXEC mode
(config-line)#	console password	Limits device access using the console connection
(config-line)#	vty password	Limits device access over Telnet
(config)#	service password-encryption	Prevents passwords from viewing as plain text when viewing the config
(config)#	banner motd #String#	This configuration results in the message of the day banner

IP ADDRESSING OF DEVICES
together with subnet mask, uniquely identify end devices on internetwork
SUBNET MASK	Determines which part of a larger network is used by an IP address
Each end device on a network must be configured with an IP address
Structure of an IPv4 address is called dotted decimal
IP address displayed in decimal notation, with four decimal numbers between 0 and 255
With the IP address, a subnet mask is also necessary
IP addresses can be assigned to both physical ports and virtual interfaces
IOS MODE	COMMAND	DESCRIPTION
(config)#	interface VLAN 1	Selects interface vlan 1
(config-if)#	ip address 192.168.10.2 255.255.255.0	assigns device IP address and subnet mask
(config-if)#	no shutdown	Administratively enables the interface
Switch still needs to have physical ports configured and VTY lines to enable remote management

INTERFACES AND PORTS
Network communications depend on end user device interfaces, networking device interfaces, and the cables that connect them
Different types of network media have different features and benefits
Ethernet is the most common local area network (LAN) technology
Ethernet ports are found on end user devices, switch devices, and other networking devices
Cisco IOS switches have physical ports for devices to connect to, but also have one or more switch virtual interfaces
SVIs; no physical hardware on the device associated with it; created in software
SVI provides a means to remotely manage a switch over a network