Cisco IOS Cookbook, 2nd Edition (2024)

FAQs

How to copy IOS from Cisco switch to TFTP server? ›

But it's more appropriately described as an enterprise networking software stack. At 190 million lines of code from Cisco—and more than 300 million lines of code when you include vendor software development kits (SDKs) and open-source libraries—IOS XE is comparable to stacks from Microsoft or Apple.

To initiate transfers of configuration files to or from a TFTP server using the CLI, enter one of the following commands: copy startup-config tftp tftp-ip-addr filename - Use this command to upload a copy of the startup configuration file from the Layer 2 Switch or Layer 3 Switch to a TFTP server.

- [Instructor] The Cisco Inner Operating System, the IOS has three command line modes, User EXEC mode, or user mode, Privileged EXEC mode, or privileged mode, and then the Global Configuration mode.

There are five command modes: global configuration mode, interface configuration mode, subinterface configuration mode, router configuration mode, and line configuration mode.

The Cisco IOS defines an interface called the Command Line Interface (CLI), which enables administrators to enter commands into a terminal emulation program. The CLI can be accessed through three methods: the console, Telnet and Secure Shell (SSH).

VLANs have the following configuration guidelines and limitations: The maximum number of VLANs per VDC is 4094.

What is the default password for Cisco IOS device? ›

When the login page opens, enter the username and password. The default username is cisco. The default password is cisco.

Lines 0 15 is vty lines 0, 1, 2 ,3 ,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15. for example if you were type in global configuration mode, line vty 0 15 you will enter configuration for lines 0-15. I hope this answers your question.

Ctrl-e To the end of the line. Ctrl-l or Ctrl-r Redraw the screen at the prompt. Ctrl-z Return to the EXEC mode from any configuration mode exit command Return to the previous mode or exit from the CLI from Exec mode. Ctrl-t Transpose a character at the cursor with a character to the left of the cursor.

It is not that Ctrl-Shift-6 has been decided on by Cisco, rather the particular terminal emulator you are using has that as the shortcut for sending the 'break' terminal escape character. For instance minicom under linux uses Ctrl-X F for the same function. cheers, Seb.

The virtual terminal or “VTY” lines are virtual lines that allow connecting to the device using telnet or Secure Shell (SSH).

The TFTP server uses well-known port 69. The TFTP server has no user authentication. Any client that can connect to port 69 on the server has access to TFTP.

The config files are retrieved and are stored in the file system under the TFTP Root directory, the default location being <OpUtils_Home>/webapps/tftp directory.

This is used to show the files in your flash. The command show flash is similar to dir flash: but it provides a little more information on the size and type of flash memory in your router. It can be a bit confusing why you would erase one type of filesystem, but format another.

IOS includes a built-in File Transfer Protocol (FTP) client that can be used to transfer images to and from the Cisco device. Unlike TFTP, FTP supports authentication, and you will need to provide a valid FTP server username and password.

What are the two types of configuration files in Cisco devices? ›

By default, Cisco routers have three levels of privilege—zero, user, and privileged. Zero-level access allows only five commands—logout, enable, disable, help, and exit. User level (level 1) provides very limited read-only access to the router, and privileged level (level 15) provides complete control over the router.

The general syntax for a command is the command followed by any appropriate keywords and arguments. Some commands include a subset of keywords and arguments that provide additional functionality. The figure shows these parts of a command.

The AAA server is a network server that is used for access control. Authentication identifies the user. Authorization implements policies that determine which resources and services an authenticated user may access. Accounting keeps track of time and data resources that are used for billing and analysis.

The CLI has two modes: Operational mode—Use this mode to display the current status of the device. In operational mode, you enter commands to monitor and to troubleshoot the network operating system, devices, and network connectivity. Configuration mode—Use this mode to configure the device.

The ROM Monitor (ROMMON) is a bootstrap program that initializes the hardware and boots the Cisco IOS XE software when you power on or reload a router. If your router does not find a valid system image to load when it is booting, the system enters the ROMMON mode.

There are two types of access control: physical and logical. Physical access control limits access to campuses, buildings, rooms and physical IT assets. Logical access control limits connections to computer networks, system files and data.

Three common controlled access protocol methods are reservation, token passing, and polling.

For a given VLAN you can assign up to 32 IP addresses. This allows you to combine two or more subnets on the same VLAN, which enables devices in the combined subnets to communicate normally through the network without needing to reconfigure the IP addressing in any of the combined subnets. Default gateway operation.

Because there are 12 bits in the VLAN ID field of the IEEE 802.1Q header, 4096 is the upper boundary for the number of VLANs available on Catalyst switches.

Can a VLAN have multiple IP ranges? ›

Multiple IP addresses allow multiple subnets within the same VLAN. You can configure IP addresses on all protocol VLANs. However, IP addressing is used only on IPv4 and IPv6 VLANs.

Type 9 is designed to make it difficult to crack the password since it requires a significant amount of hardware resources to do so, raising the cost for an adversary to brute force. The passwords are stored as hashes within the configuration file. Cisco and industry recommend Type 9 hashes.

Cisco type 7 password

This password type uses Vigenère cipher which is essentially a simple alphabetical substitution encryption. The algorithm is reversible and thus it can be deciphered instantly into a plain text without any need for cracking.

TTY is a physically connected one, via the serial/console port. VTY is a virtually connected one, via telnet or SSH. Both will get you to a command line interface.

VTY is solely used for inbound connections to the device. These connections are all virtual with no hardware associated with them. The abstract “0 – 4” means that the device can allow 5 simultaneous virtual connections which may be Telnet or SSH.

VTY lines are usually used for creating out-of-band management sessions to devices. If a password is not supplied on a vty line, that line cannot be used for managing the device. In some cases administrators may decide to let junior staff to use lines 0 - 4 and senior staff to use lines 5 - 15.

Press Ctrl + 6 or Ctrl + 6, X. You first need to change or disable the 'Ctrl + [1… 9]' shortcut (see below). Once you do that, use Ctrl + 6 or Ctrl + 6, X to send break sequences.

Ctrl-Shift-6

All-purpose break sequence. Use to abort DNS lookups, traceroutes, pings.

Command-V: Paste the contents of the Clipboard into the current document or app. This also works for files in the Finder.

What does Ctrl Shift +H do? ›

The Ctrl+Shift+H keyboard shortcut is used to open the Library window in Firefox.

What is Ctrl+E? Ctrl+E is a keyboard shortcut that centers the contents of a selected cell. This shortcut is particularly useful when you're working with large amounts of data and need to quickly format cells to make them more readable.

Ctrl+Shift+T

Opens the tab in a new window. Opens the tab in the existing window. Returns the tab to its original position. Switches to the tab at the specified position number on the tab strip.

To disable VTP, enter the set vtp domain domain name mode transparent command. This disables VTP from the domain, but does not remove the domain from the switch. Use the clear config all command to remove the domain from the switch. Be careful when you use the clear config all command.

Above we can see the new IOS image. The copy command also allows you to enter parameters like the IP address of the TFTP server and filenames. Here is an example: R1#copy tftp://192.168.1.200/c2800nm-adventerprisek9-mz.151-4.M12a.bin flash: Destination filename [c2800nm-adventerprisek9-mz.

IOS configurations are usually copied to a TFTP server using the copy command. You can backup both the startup configuration and the running configuration of your device. The copy command accepts two parameters: the first parameter is the from location, and the second it the to location.

How do I get files from TFTP server? ›

The TFTP server uses well-known port 69. The TFTP server has no user authentication. Any client that can connect to port 69 on the server has access to TFTP.

To initiate transfers of configuration files to or from a TFTP server using the CLI, enter one of the following commands: copy startup-config tftp tftp-ip-addr filename - Use this command to upload a copy of the startup configuration file from the Layer 2 Switch or Layer 3 Switch to a TFTP server.

A TFTP server is a necessary tool that every administrator should use to periodically back up their Cisco router and switch configuration files and IOS files.

As mentioned, TFTP uses UDP as a transport, as opposed to TCP which FTP uses, and works on port 69, you can clearly see that in the cool 3D diagram on the left. Port 69 is the default port for TFTP, but if you like, you can modify the settings on your TFTP server so it runs on a different port.

The config files are retrieved and are stored in the file system under the TFTP Root directory, the default location being <OpUtils_Home>/webapps/tftp directory. TFTP Server tool can be used to view the contents of the TFTP Root directory.

You will use the copy command to do the remote upgrade. You will telnet to the router, get into enable mode, and issue the copy command which will do the upgrade.