Wednesday, February 10, 2016

CCNAv1 Chapter 2 Notes - Cisco IOS

Chapter 2
# 9/9/2015
Cisco iOS
  • Location: Flash (Non-Volatile)
  • On Bootup – Copied into RAM (Volatile)
  • The iOS is ‘real time’.

Two kinds of configurations
Startup Configuration
Running Configuration
  • To save changes for next

Three Methods to Connect to a Cisco IOS Device
  • Console
  • Telnet/SSH
  • Auxiliary Port

  • Uses the network.
  • Goes to PC to Router/Switch/PC
  • Virtual connection to another device (see above).
  • Console port is the only way an initial configuration can be done.
  • Requires a terminal emulator.

Terminal Programs (Access)
  • Putty, HyperTerminal, & “TeraTerm”

Telnet: Connections via network using terminal software.
Console: Direct connect to the console port.
Aux: Connecting using dial-up adapter.
SSH: Secure version of Telnet.

Cisco iOS (Part 2)
Only accepted passwords will be ‘class’ or ‘cisco’.
Listed from LOWEST to HIGHEST access levels.

(Important) IOS TYPES
Prompt Mode of Operation Command/INF (example)
  • Router> User Exec Mode
  • Router#> Privileged Exec Mode ‘enable’
  • Router(config)#> Global Configuration Mode ‘configure terminal’
  • Router(config-if)#> Interface Configuration Mode ‘interface f0/0’
  • Router(config-line)#> Line Configuration Mode ‘line console 0’

You will only use ‘enable’ with “Router>”. You will then move on from “Router#>” to where needed.
Use Context Sensitive Help

Device Naming
General rules for device names.
  • Starts with a letter.
  • No spaces.
  • Ends with a letter or number.
  • ONLY use letters, numbers, or dashes.
  • Less than 64 digits.

# 9/10/2015

Flash Memory is non-volatile.

Four Connection Methods
  • Console, Telnet, SSH, Aux

Inband and outband network:
  • Inband
    • Uses the network.
    • Requires one functioning ethernet port.
  • Outband
    • Does not use the network.

  • Console is direct connection.
  • Aux uses phone lines.
  • Telnet/SSH uses inband (network).

Cisco iOS Scenarios / Questions
View the configuration setup:
  • show running-configuration
  • show startup-configuration

What can be password protected?
  • Access the console interface.
  • Privileged exec mode.
  • VTY Lines.
  • Aux Lines.

How Passwords Come in Order:
  • CLI Opens,
  • Enter
  • R1> Enable
  • PASSWORD! (Privileged Exec)

How to view your Banner:
  • When does the banner show up?
    • When it boots. (After ‘Enter’, mostly)
  • How do you get there if you’re in global config?
    • Exit global config until you reach the beginning.

When do changes affect the running configuration?
  • Immediately afterwards.

You make changes to the configuration and notice that it is not working. Options?
  • Use the command called ‘reload’.

DHCP assigns IP addresses automatically. No station manual configuration needed.

With this in mind, how would you have an IP Addressing Scheme?
  • Public addr vs/with private address
  • Within that local network, two devices cannot have the same IP on the local network.

(CMD) A very helpful command is ipconfig, and ipconfig /all.
(CMD) Ping is also useful.

Layer 2 - MAC (Physical)
Layer 3 - IP (Logical)

What do I need to telnet to a Layer 2 switch?
  • Network & Terminal Client needed

An SVI is a Switch Virtual Interface. VLAN1 is an SVI. You can assign an IP to VLAN1.

Hotkeys / Shortcuts
  • TAB
    • Auto completes a command.

  • Ctrl + Z
    • Puts you to privileged exec mode.
  • Up Arrow
    • Cycle through previously entered commands.

  • Ctrl + C
    • Cancels a command you’re working on. Takes to exec mode.

  • Ctrl + R
    • Redisplay, on a new line, the command you are currently typing.

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