> For the complete documentation index, see [llms.txt](https://cisco.microcisco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cisco.microcisco.com/icnd-1/cisco-ios-software.md).

# Cisco IOS Software

Connection to a router, boot-up an various options including basic IOS commands, modes (user mode / privilege mode) etc

## Informational

* Console cable is a "roll over" cable. The pin-outs are 'rolled over' 
  * Pin 1 --> Pin 8
  * Pin 2 --> Pin 7
  * Pin 3 --> Pin 6
  * Pin 4 --> Pin 5
  * Pin 5 --> Pin 4
  * Pin 6 --> Pin 3
  * Pin 7 --> Pin 2
  * Pin 8 --> Pin 1
* Terminal Emulation
  * Hyper-terminal - Limited (Comes with Windows)
  * Putty - only runs on Windows
  * Terra Term - Free
  * SecureCRT - Windows and MacOS
  * iTerm
  * Royal TSX

![](https://4011257951-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LtfmTuncdFr6DnNyt_b%2F-MG7ZZmK4RXoHMZChE2b%2F-MG7kpnQ-Iahh-uWn3IB%2Fimage.png?alt=media\&token=ca14f3a0-fe2d-4a9b-a2f5-971d43267223)

![](https://4011257951-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LtfmTuncdFr6DnNyt_b%2F-MG7ZZmK4RXoHMZChE2b%2F-MG7kwmRZXeXELnzYpYe%2Fimage.png?alt=media\&token=b9836fdb-ba30-453c-b0e7-3895cffc271b)

### Modes

* User Mode: Router>
  * view only mode
  * limited set of commands
  * basic monitoring commands
* Privilege Mode (Enable Mode): Router#
  * allows a lot more show commands
  * allow debugging
  * used to configure the device
* Global Config Mode: Router#(config)
  * change global parameters
  * MOTD (message of the day) - should be a legal entity. You can use any delimiter like hash (#) , a letter like 'c' etc and have to end with the same delimiter.
* Line Mode - remember to use the 'login' parameter to use the password feature
  * console (console)
  * vty 0 4 (Used for telnet and ssh access)
    * login
    * password cisco
    * input transport telnet ssh

### Useful Shortcuts

![](https://4011257951-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LtfmTuncdFr6DnNyt_b%2F-M175SRaH12Zq591QpGl%2F-M17QJ_j4M4_Zf3xsUKX%2Fimage.png?alt=media\&token=512be52b-78c5-4910-aa7d-fc74b682d85a)

* Other useful commands

  * Ctrl-U = deletes an entire line
  * Ctrl-C = cancels the command
  * Ctrl+Shift 6 x = breaks a command (like issue with domain lookup - arrgghhhhhhhhh)

## Managing Cisco IOS Configuration

* Running Config and Startup Config
  * copy run start (from RAM to NVRAM - overwrites the NVRAM config)
  * copy start run (**merges** the NVRAM with the RAM config)
* show start run | b vty  ---- b = ***begin*** 
  * line vty 0 4
  * login
  * !
  * end
* \#config replace nvram:startup (**replaces** the config)
* \#erase startup-config
* \#copy run tftp\://192.168.1.1/\<config\_name>
  * copy run tftp to copy start tftp = override or replacement
  * copy tftp to running config = merge
  * copy tftp replace = will replace the configuration file

### Storing Files in Flash

* show flash
  * copy running-config flash:/run1.cfg
    * more flash:run1.cfg will show the contents of the config file

### Terminal Length & No IP Domain Lookup

When you do a show run, by default the config is restricted to a certain amount of lines (24) and it will then give out the --more-- command and then press spacebar and the next 24 lines will show etc etc

A tip is to use the command # **terminal length 0**, which shows the ENTIRE config in one go (good if you have long configurations etc)

Another tip is to use #**no ip domain lookup** when the router takes a long time to time out after trying to resolve a mistake you typed into a domain name!!

### Basic Device Security

* (config)#**service password encryption**
  * not very secure as it encrypts enable password  with a type 7
* (config)#**enable secret**  CISCO
  * will see a 5 (md5) in front of encrypted password.&#x20;

If you have both "enable password" and "enable secret" configured - the IOS will only use the "enable secret" password and ignore the other

![](https://4011257951-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LtfmTuncdFr6DnNyt_b%2F-MG7ZZmK4RXoHMZChE2b%2F-MG7iX5lXxbg7pp2-o0O%2Fimage.png?alt=media\&token=68013734-3a2c-4925-b382-b300ef555647)

![](https://4011257951-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LtfmTuncdFr6DnNyt_b%2F-MG7ZZmK4RXoHMZChE2b%2F-MG7kZUxd7s9nU6UrNVo%2Fimage.png?alt=media\&token=159f52e8-1412-4737-98d0-a210817baf9c)

## LAB

[Packet Tracer file](https://1drv.ms/u/s!Ah-1dyhzDaLDpS6XSSMYm2soszx8?e=e9keqx)

![](https://4011257951-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LtfmTuncdFr6DnNyt_b%2F-MG7ZZmK4RXoHMZChE2b%2F-MG7mTAsKHQn-SD1QjIf%2Fimage.png?alt=media\&token=a90309b3-258b-48c3-a5cf-6a06979f7858)