Command Line Interface

You can configure the Cisco Nexus 3550-T Programmable Switch Platform via the CLI. You can access this interface via SSH, telnet, or an industry standard serial interface.

Configuration Mode

By using the CLI, you can inspect the current configurations of the Nexus 3550-T and also modify the configuration.

You can use the CLI in either a modal or non-modal way. For example, commands that change the current configuration are prefixed with config. When executing multiple configuration commands, it is convenient to enter config mode. For example, to disable an interface, enter the following command:

admin@NX-3550-T# configure interface ethernet1 shutdown
Interface "ethernet1" disabled

Alternatively, enter the config mode and then disable the interface:

admin@NX-3550-T# config
admin@NX-3550-T(config)# interface ethernet1 shutdown
Interface "ethernet1" disabled

Note

In the above example the CLI prompt indicates that config mode is in use. To exit the mode, simply type exit.

  admin@NX-3550-T(config)# exit
  admin@NX-3550-T#

Additionally, a shortcut is available to exit any mode, which is by pressing Control+d.

Note

When you exit the config mode, the interface drops back to the default mode. Importantly, if you type exit within the default mode, you will log you out of the device.

You can nest modal states. When you use the exit command, you drop out of that level and go up to the previous level. To drop out of all levels and return to the top modal level, use the end command.

admin@NX-3550-T# config
admin@NX-3550-T(config)# interface ethernet1
admin@NX-3550-T(config-if-et1)# end
admin@NX-3550-T#

Help and Autocompletion

The CLI includes help and tab autocompletion.

Help

While using the Nexus 3550-T, access the help by entering the ? command. If multiple parameter options that are valid from that point on are available, entering ? will list those options.

admin@NX-3550-T# configure interface management1 ?
  interface  Configure interfaces
  exit       Exit management network configuration mode
  end        Exit configuration mode
  no         Negate a command or set to defaults
  ip         Configure IPv4 settings
  ipv6       Configure IPv6 settings

If no further valid parameter options are available when you enter ?, the detailed usage information is displayed:

admin@NX-3550-T# configure interface management1 ip address ?
<a.b.c.d/n>  IPv4 address and prefix length

Autocompletion

For autocompletion and to get suggestions for any command, press tab after entering any partial command. In this example, the interface shows a list of available ports after you press tab:

admin@NX-3550-T# config interface
ethernet1    ethernet2    ethernet3    ethernet4    ethernet5    ethernet6
ethernet7    ethernet8    ethernet9    ethernet10   ethernet11   ethernet12
ethernet13   ethernet14   ethernet15   ethernet16   ethernet17  ethernet18
ethernet19   ethernet20   ethernet21   ethernet22   ethernet23  ethernet24
ethernet25   ethernet26   ethernet27   ethernet28   ethernet29  ethernet30
ethernet31   ethernet32   ethernet33   ethernet34   ethernet35  ethernet36
ethernet37   ethernet38   ethernet39   ethernet40   ethernet41  ethernet42
ethernet43   ethernet44   ethernet45   ethernet46   ethernet47  ethernet48
vlan1        vlan10       vlan100      breakout     management1  management2

Command Pipelines

The CLI supports redirecting command output to standard UNIX utilities, such as grep and less.

admin@NX-3550-T# show interface ethernet1 | grep Speed
Speed is 10000 Mbps

Because this feature allows you to run arbitrary shell commands, it is available only to users who have admin privileges.

SSH Keys

To authenticate your login into the Nexus 3550-T, you can use SSH keys, rather than entering a password. To authenticate with SSH keys, add your public key into the Nexus 3550-T, for example:

admin@NX-3550-T# config user admin sshkey "ssh-rsa AAAAB3NzaC1yc2EAAAA
DAQABAAABAQC15sjG4cYSAbYU0VIwPkdQkIKb0A2xxhPCjOAnzt91CrRQZibirZNqqW71TX3QVt
Ruqp2ZQjo19Nd9bk2iwa3qDITQIOlRdSJgwEBdklfgjkrjkd8KLSDfklwjkrjksjkXyztI3sKRM
mcYOEFjt9Bv+5JPw3o3Pja5GQOO5VEjM//QhsbMZ+G/4Sfx5GiLTaktenqNWflPaMcDWqq1wuuf
6mG7lEM55UDp5xWRrh5vIfyOh9Llosdfsasjkejk89sv9+cjkfhjksjhcjkhskhkljashdfiuhs
dfv98734kjFDjhjhdjhbfjh489jkJKZDJKHFVjkhi6SBbTu5v9 bob@myserver.com"
Added ssh key for user "admin"

After configuring the SSH keys, you can login without being prompted for a password.

$ ssh admin@NX-3550-T
admin@NX-3550-T>

To remove an SSH key for a user, use the 'no-' form of the sshkey command, and pass the public key that you need to remove.

admin@NX-3550-T> config user admin no sshkey "ssh-rsa AAAAB3NzaC1yc2EA
AAADAQABAAABAQC15sjG4cYSAbYU0VIwPkdQkIKb0A2xxhPCjOAnzt91CrRQZibirZNqqW71TX3
QVtRuqp2ZQjo19Nd9bk2iwa3qDITQIOlRdSJgwEBdklfgjkrjkd8KLSDfklwjkrjksjkXyztI3s
KRMmcYOEFjt9Bv+5JPw3o3Pja5GQOO5VEjM//QhsbMZ+G/4Sfx5GiLTaktenqNWflPaMcDWqq1w
uuf6mG7lEM55UDp5xWRrh5vIfyOh9Llosdfsasjkejk89sv9+cjkfhjksjhcjkhskhkljashdfi
uhsdfv98734kjFDjhjhdjhbfjh489jkJKZDJKHFVjkhi6SBbTu5v9 bob@myserver.com"
Removed ssh key for user "admin"

This page was last updated on Mar-23-2021.