MigrationBot: Backfill (v3.0 review queue): added to the review queue

2026-09-22T05:43:02Z

Backfill (v3.0 review queue): added to the review queue

← Older revision		Revision as of 05:43, 22 September 2026
Line 132:		Line 132:
	[[Category:Cisco Packet Tracer\|039]]		[[Category:Cisco Packet Tracer\|039]]
	[[Category:Migrated from cypat.guide]]		[[Category:Migrated from cypat.guide]]
			[[Category:Pending review]]

MigrationBot: Import from cypat.guide: docs/cisco/Cisco Packet Tracer/intro_ios.md

2026-09-18T18:18:47Z

Import from cypat.guide: docs/cisco/Cisco Packet Tracer/intro_ios.md

New page

{{Submit}}


Author(s): a_person

Last Updated: 08-09-2025

{| class="mw-collapsible mw-collapsed wikitable" style="width:100%"
! Recommended Prerequisites (click to expand)
|-
|

None

|}

== What is an OS? ==

An operating system (OS) is system software that manages computer hardware and software resources. Cisco has its own operating system, Cisco IOS, and it is used on their devices, which include routers, switches, and firewalls.

== Access methods ==

=== Console ===

A physical management port that offers out-of-band access to a Cisco device via a dedicated management channel used solely for maintenance. The main benefit is that the device can be accessed even if no network settings are configured, such as during initial setup. To connect, you'll need a computer with terminal emulation software and a special console cable.

=== Secure Shell (SSH) ===

An in-band, secure method to remotely access the device’s CLI over a network through a virtual interface. SSH requires the device to have active networking services and a configured interface with an IP address. Most Cisco IOS versions include both an SSH server and client for establishing secure sessions. SSH is not only used in networking devices, and can be used to access servers.

=== Telnet ===

An insecure, in-band way to remotely access the CLI over a network via a virtual interface. Unlike SSH, Telnet does not encrypt data, so passwords and commands are sent in plaintext, making it suitable only for enviornments like labs. SSH is strongly recommended instead.

== Terminal Smulation Software ==

These provide a more graphical way to interact with devices. The most common emulation software is [https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html PuTTY].

== Cisco Command Modes ==

There are 3 main Command Modes:

=== User EXEC Mode ===

* Indicated by the <code>></code> symbol. Example:

<syntaxhighlight lang="text">Router></syntaxhighlight>
* Limited in what you can do
* The user can view basic information about the device, but can't make changes to the configuration.

=== Privilaged EXEC Mode ===

* You can enter this mode through using the '''enable''' command, and exit through '''disable''' or '''exit'''.
* Indicatedby the <code>#</code> symbol. Example:

<syntaxhighlight lang="text">Router#</syntaxhighlight>
* Provides complete access to view the device's configuration, restart the device, etc.
* Cannot change the configuration, but can change the time on the device, save the configuration file, etc.

=== Global Configuration Mode ===

* You can enter this mode through using the '''configure terminal''' command, and exit through '''disable''' or '''exit'''.
* Indicated by <code>(config)#</code> . Example:

<syntaxhighlight lang="text">Router(config)#</syntaxhighlight>
* Provides complete access to view the device's configuration, restart the device, etc.
* Cannot change the configuration, but can change the time on the device, save the configuration file, etc.
* Provides access to change the device's running configuration, including interface settings, routing protocols, and security configurations.

== Help Command ==

* Single question mark (?) shows available commands or options at the current level. Example:

<syntaxhighlight lang="text">Router> ?</syntaxhighlight>
This will show all the avaliable commands that you can use in the currrent state.

<syntaxhighlight lang="text">Router> show ?</syntaxhighlight>
This will show you what parameters are accepted for the show command.

<syntaxhighlight lang="text">Router> s?</syntaxhighlight>
This will show you all the possible completions of the command.

== Do command ==

The do command allows you to execute commands in privileged EXEC mode commands without leaving configuration modes.

Example: Checking the running configuration while in interface configuration mode:

<syntaxhighlight lang="text">Router(config-if)# do show running-config</syntaxhighlight>
== Shortening Commands ==

Many Cisco IOS commands can be abbreviated as long as the abbreviation is unambiguous.

Example:

<syntaxhighlight lang="text">Router> show running-config</syntaxhighlight>
can be shortened to:

<syntaxhighlight lang="text">Router> sh run</syntaxhighlight>
Use ? to confirm what abbreviations are valid.

== Hostname command ==

You can name the router/switch by using <code>hostname</code>

Example:

<syntaxhighlight lang="text">Router(config)#hostname CiscoRouter1</syntaxhighlight>
== Updating the Running configuration ==

You can do this through <code>copy running-config startup-config</code> and <code>write memory</code>. These can be abbreviated to <code>copy run start</code>(now you know why people say it) and <code>wr</code>

== Practice ==

Do the following steps in order:

# Enter privilaged EXEC mode
# Enter global configuration mode
# Exit global configuration mode
# Exit privilaged EXEC Mode

'''You must enter the FULL commands.'''

'''Interactive practice:''' [https://orionband.github.io/windowstst/cisco.html?q=enable:configure%20terminal:exit:exit,enable:configure%20terminal:exit:disable,enable:configure%20terminal:exit:disable Open the practice widget (external site)]

== Supplementary Resources and Further Reading ==

* https://www.cisco.com/E-Learning/bulk/public/tac/cim/cib/using_cisco_ios_software/02_cisco_ios_hierarchy.htm
* https://www.cisco.com/c/en/us/td/docs/switches/wan/mgx/mgx_8850/software/mgx_r3/rpm/rpm_r1-1/configuration/guide/appc.pdf
* https://www.youtube.com/watch?v=IYbtai7Nu2g&list=PLxbwE86jKRgMpuZuLBivzlM8s2Dk5lXBQ&index=8

[[Category:Cisco Packet Tracer|039]]
[[Category:Migrated from cypat.guide]]

Draft:An Introduction to Cisco IOS - Revision history

MigrationBot: Backfill (v3.0 review queue): added to the review queue

MigrationBot: Import from cypat.guide: docs/cisco/Cisco Packet Tracer/intro_ios.md