Chapter 2 Flashcards
Router:
Forwards data packets to and from the Internet.
Home routers are actually 4 devices in one. What are they?
- Router
- Switch
- Wireless access point
- Firewall appliance
Switch:
Connects end devices using network cables.
Wireless access point:
consists of a radio transmitter capable of connecting end devices wirelessly.
Firewall appliance:
Secures outgoing traffic and derricks incoming traffic.
CISCO operating system.
CISCO internetwork Operating System (IOS)
Operating System breakdown.
- Shell
- Kernel
- Hardware
Shell:
The user interface that allows users to request specific tasks from the computer. Through CLI or GUI interfaces.
Kernel:
Communicates between the hardware/software of a computer and manages how hardware resources are used to meet the requirements of software.
Hardware:
Physical part of a computer, including underlying electronics.
IOS is stored in:
Flash
What is Flash?
- Non-volatile storage. (Not list when power goes out)
- can be changed or overwritten as needed.
- can be used to store multiple versions of IOS.
- IOS copied from flash to volatile RAM
- quantity of flash and RAM memory determines IOS that can be used.
Functions performed by CISCO routers/switches.
- provides network security
- IP addressing of virtual and physical interfaces.
- enabling interface specific configurations to optimize connectivity of the respective media.
- routing
- Enabling QoS technologies.
- supporting network management technologies.
Most common methods to access the Command Line Interface (CLI).
- Console
- Telnet or SSH
- AUX port
Console Port Access method. Everything about it.
- Device is accessible even if no networking services have been configured (out-of-band).
- can also be used when the networking services have failed and remote access of the device is not possible.
- requires a special console cable linked to a device running terminal emulation software.
- should be configured with passwords to prevent unauthorized access.
- device should be located in secure room.
Telnet access method.
Method for remotely accessing the CLI over a network.
Require active networking services and one active interface that is configured.
Secure Shell (SSH) access method.
- Remote login, similar to telnet, but utilizes more security measures.
- stronger password authentication
- uses encryption when transporting data.
Aux port access method.,
- out of band connection.
- provides modem access via a telephone line.
- can be used like a console port, with a direct connection to a device running emulation software.
Examples of Terminal Emulation Programs.
- PuTTY
- Tera Term
- SecureCRT
- HyperTerminal
- OS X Terminal
CISCO IOS Modes of Operation, in order.
- User EXEC
- Privileged EXEC
- Global Configuration
- Specialize modes.
User EXEC mode abilities.
Basic monitoring commands. Aka “View-only” mode.
Privileged EXEC mode abilities:
By default allows monitoring commands as well as execution configuration and management commands.
Forms of help IOS provides.
- context sensitive help(?)
- command syntax check
- hot keys and shortcuts.
Host names of devices must meet these requirements: (pretty simple don’t overthink)
Start with a letter
No spaces
End with letter or digit
Use only letters, digits, and dashes
Less than 64 characters
