Cisco VTY Configuration Commands

Cisco IOS CLI Commands and Functions

• The help command provides information on available commands and arguments in user EXEC, privileged EXEC, and global config modes.
• Commands and arguments can be completed in Cisco IOS CLI by using the Tab key to auto-complete or by using the ? symbol to display available options.
• Hot keys and shortcuts are used in the IOS CLI to increase efficiency and reduce typing.
• The Tab key auto-completes commands and arguments in the IOS CLI.
• The → key moves the cursor one character to the right in the IOS CLI.
• Commands and keywords can be shortened in the IOS CLI by using abbreviations.
• The Ctrl+Z keystroke is used to end the configuration mode and return to privileged EXEC mode in Cisco IOS.
• When the --More-- prompt is displayed, pressing any other key scrolls down the output.
• The Ctrl+[ keystroke is an all-purpose break sequence used to abort DNS lookups, traceroutes, pings, etc. in Cisco IOS.
• Pressing the Space Bar when the --More-- prompt is displayed shows the next page of output.
• Pressing the Return key when the --More-- prompt is displayed shows the next line of output.

Cisco IOS Configuration and Security

• The password command is used to specify the VTY password.
• VTY access can be enabled on a Cisco device by using the line vty command.
• The service password-encryption command is used to encrypt plaintext passwords in Cisco devices.
• A banner message is important on a network device to provide a warning or information to users.
• The startup-config file on a Cisco switch stores the configuration that is loaded when the device boots up.
• Many Cisco switches support 16 VTY lines.
• The running-config file is stored in RAM on a Cisco switch.
• The delimiting character used when creating a banner message on a Cisco device is ^.
• The content of RAM is lost when a Cisco device is powered off or restarted.
• Changes made to the running-config file can be saved to the startup-config file by using the copy running-config startup-config command.
• The running-config file is modified immediately when changes are made to the configuration of a Cisco device.
• RAM on a Cisco switch is a type of volatile memory.

IPv4 and IPv6 Addressing

• The network portion of an IPv4 address is differentiated from the host portion by the subnet mask.
• IPv6 addresses are written in hexadecimal notation, separated by colons.
• The default gateway address is used to forward packets to other networks.
• IPv6 addresses are 128 bits long.
• IPv6 is the newer version of the IP protocol, replacing the more common IPv4.
• Dotted decimal notation refers to the way IPv4 addresses are written in dotted decimal format.