Command Show Running-Config Interface Use Shows the current configuration of a given interface on the router. This command is useful because it reduces IOS’s output to just show you the interface information. Read the filtering page under the show command section for more information on further ways to …

Command Show Access-Lists Use This command displays information about the access-lists that are configured on a router. It also shows information about what lines are matching in the ACL. Syntax Router#show access-lists OR Router#show access-lists <number or name> Example In the below example we use show access-lists to see what …

Command Access-Class Use Specifies which hosts can telnet/ssh into the vty. Syntax Router(config-line)#access-class <list> <in or out> Options <in> Applies the access-list to inbound traffic on the interface. <out> Applies the access-list to traffic leaving the router. Example In this example, an access-class is created on R2.. R2#conf t …

Command Lockable Use Enables vty session locking. Syntax Router(config-line)#lockable Usage Before using the Lock command, you must first enable it by typing lockable under the console or VTY lines Type Lock You will be prompted to set a password. This is a one-time use password and shouldn’t be a password already on the …

Command History Size Use Sets the number of previous commands stored in the session history. These commands can be viewed by pressing the up arrow key. Syntax Router(config-line)#history size <0-256> Example In the example below the history size is set for the vty. R2#conf t Enter configuration commands, one per line. …

Command Length Use Sets the amount of lines outputted at once in a vty session. Setting the line to 0 will mean that commands will print all of the output at once in the vitual terminal screen. Syntax Router(config-line)#length <number> <number> 0-512 Example In this example the line of vty 0 …

Command Login Use Enables authentication for virtual terminal connections to router. Contrary to what it may sound like, using the no login command will actually disabled authentication to the vty line. This means that a user will not be prompted for a password when trying to log in to the …

Command Password Use Sets the password for virtual terminal login. Syntax Router(config-line)#password <password> Example In this example a password is set for vty 0 4 login on R2. R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#line vty 0 4 R2(config-line)#password cisco The config is shown …

Command Exec-Timeout Use Sets the timeout period for virtual terminal session inactivity. Syntax Router(config-line)#exec-timeout <minutes> <seconds> <minutes> 0-35791 <seconds> 0-2147483 Example In this example an exec-timeout is set for console 0. R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#line vty 0 4 R2(config-line)#exec-timeout 15 50 R2(config-line)#

Command Logging Synchronous Use When enabled on a virtual terminal, logging synchronous causes all router status messages to be displayed on a new line. Syntax Router(config-line)#logging synchronous Example For this example, logging synchronous was disabled for vty 1 on R2. R2(config-line)#no logging synchronous Notice now that, when status …