Configuration management

Showing and saving the current config

The configuration of the Cisco Nexus 3550-H Hydra (formerly ExaLINK Hydra) is described by a running-config. The running-config contains all of the settings that are currently in effect on the device.

admin@EXALINK-HYDRA# show running-config
interface breakout ethernet1 map 10g-8x
interface ethernet1/1
speed 10000
interface ethernet1/2
speed 10000
tap ethernet1/1 ethernet1/2
hostname hydra5
ip name-server
interface management1
ip address gateway
interface management2
ip address

Given the considerable number of interfaces available in the Nexus 3550-H, the full output of show running-config may be more verbose than the user requires. Users may examine the configuration of a particular interface via:

admin@EXALINK-HYDRA# show running-config interface ethernet1/1
interface ethernet1/1
  speed 10000

This command can also be combined with range selectors, to show the configuration of a number of interfaces. See Configuring interfaces for more detail.

admin@EXALINK-HYDRA# show running-config interface ethernet1/1-4
interface ethernet1/1
  speed 10000
interface ethernet1/2
  speed 10000
interface ethernet1/3
  speed 10000
interface ethernet1/4
  speed 10000

Users may also inspect the running configuration of any patch or tap objects that have been created. For example:

admin@EXALINK-HYDRA# show running-config patch
patch ethernet1/1 ethernet2/1
patch ethernet1/2 ethernet2/2
patch ethernet1/3 ethernet2/3
patch ethernet1/4 ethernet2/4
patch ethernet1/5 ethernet2/5
patch ethernet1/6 ethernet2/6
patch ethernet1/7 ethernet2/7
patch ethernet1/8 ethernet2/8

It it worth noting that as mentioned on the Command line interface page, the output of these commands can be redirected into Unix utilities such as grep and less, for improved readability. For example:

admin@EXALINK-HYDRA# show running-config | grep management -A 1
interface management1
  ip address gateway
interface management2
  ip address

To make the running-config persistent across reboots of the device, it must be saved to the startup-config. To save the running-config to the startup-config, use the copy command:

admin@EXALINK-HYDRA# configure copy running-config startup-config
Saved running config to startup config

Any setting in the startup-config will be applied to the device at boot time.

Creating custom configurations

Users may create custom configurations by copying existing configurations. The running-config and startup-config may be used to accomplish this:

admin@EXALINK-HYDRA# config copy running-config myconfig
Saved running config to "myconfig"

These configurations can then be applied to the running-config or startup-config to apply them.

Erasing configurations

Along with custom configurations created by the user, startup-config can be erased with the erase startup-config command. This command will revert the Nexus 3550-H's power-up settings to the factory default settings.

Various elements of the running-config can be erased, depending on how much of the config you want to reset.

admin@EXALINK-HYDRA(config)# erase running-config
Usage: erase startup-config
       erase running-config [all] [management] [data-plane]
Erase configuration files
  • all will reset the running-config to the factory default settings, potentially rendering the device inaccessible from the current connection.

  • management will reset only those parts of the running-config related to the management of the device, not the high speed interface config. For example, hostname management address, passwords, logging etc are all covered in this reset group. This could potentially render the device inaccessible from the current connection.

  • data-plane will reset all interface configs and delete all patch and tap objects.

Backing up the config

The startup-config is stored within the Nexus 3550-H as a number of .json files in the /mnt/persist/config/ directory. These can be retrieved from the device using scp or sftp for backup purposes, and put back onto the device if necessary.

To retrieve the config files via scp run:

$ scp admin@EXALINK-HYDRA:/mnt/persist/config/*.json ./

To retrieve these files via sftp run:

$ sftp admin@EXALINK-HYDRA
admin@EXALINK-HYDRA's password:
Connected to admin@EXALINK-HYDRA.
sftp> get /mnt/persist/config/*.json

This page was last updated on Feb-18-2021.