Mastering the TNSR® Command Line Interface (CLI)

In the next brief example, router is the hostname, and the mode section of the prompt is shown changing when a command enters or exits a mode.

Command History

The TNSR CLI stores the last 300 commands across sessions. This command history is kept in ~/.tnsr_history.

You can access the command history by pressing Ctrl-P (to see the previous command), Ctrl-N (to see the next command), or by using the up and down arrow keys.

Command Completion

The TNSR CLI supports case-sensitive tab expansion and prediction for input to speed up interactive work. For example, you can type the first few letters of a command or entity (depending on the context), and then press the tab key to complete a portion or all of the remaining input where possible. You can also shorten commands or entities provided the input is not ambiguous.

Type ? to show possible completions of the current command when in the middle of a word, or type it between words to show the next available parameter.

In the following example, the user starts typing a command wr and types ? to see all possible combinations of commands available. The user then presses tab, and the TNSR CLI autocompletes the command:

Keyboard Shortcuts

The TNSR CLI supports several CLI navigation and editing key combinations, including:

Searching and Filtering Output

TNSR show commands allow additional modifiers using ‘|’ (pipe character).

Use count to display the number of lines in the show command output.

Use exclude to exclude unwanted lines.

Use match to filter the output, displaying only lines matching the pattern(s) you specify. Use regex for specific patterns.

Use tail to display the last lines of the show command output. The following example displays the last eight lines of the output (last line happens to be empty).

Configuration and Management

Configuration Database

TNSR software maintains three separate configuration databases: startup, candidate, and running. These files are stored as XML in /var/tnsr/. 

• Startup configuration is loaded when the host boots up.
• Candidate configuration is the in-process potential configuration that exists while the TNSR configuration is being actively edited. When committed, TNSR will accept this configuration as the running configuration if it is free of errors.
• Running configuration is the active running configuration, which reflects the current TNSR state.

Saving Configuration

For changes to persist between reboots of the TNSR host, the running configuration must be copied to the startup configuration, as shown in this example:

There is a shortcut command for copying running to startup, which may be familiar to Cisco IOS users:

Viewing Configuration

To view the configuration databases in CLI format, use the show configuration command followed by the database name. For example:

Or use the shortcut to specify the running configuration:

In addition to the CLI format, TNSR can display JSON or XML format as well. Simply add json or xml at the end of your command as shown in the following example:

TNSR CLI can display specific portions of the configuration. This feature is based on the Clixon YANG model. If you start typing the show run command and press tab you will see the list of YANG modules, sometimes called containers:

Running configuration can be displayed for each of these specific modules. As an example let’s show the running configuration for the nacm module in CLI/JSON/XML formats:

Some of the show commands have brief or verbose versions.

Configuration History

TNSR can track configuration history using Git. Depending on user preference, this history can be used in either a manual or automated manner. Stored versions can be manually loaded to roll back to earlier configurations as needed.

Let’s look at a real-world scenario to demonstrate this feature. In the following example, we’ll save the current configuration, make a change to it, save the new configuration, and finally, revert back to the original configuration:

Step1 Take a snapshot of the current configuration state. Initially the state of the lan2 interface is Admin disabled:

To take the snapshot:

Step 2 Enable the lan2 interface and take a new snapshot:

We can see the two snapshots, before and after our change:

Step 3 Execute a diff check of our snapshots.

For those of you who are familiar with the Git diff output, this output will be easy to read. Regardless, the output is quite self-explanatory. “-” and “+” signs indicate what lines were removed and added from the running configuration database file (running_db). In the case of our example, enable false was replaced with enable true:

Step 4 Restore to the initial configuration state.

Finally, let’s restore Initial configuration state and make sure that interface lan2 is Admin disabled:

This feature provides robust running configuration management and allows network engineers to back up, manage, and roll back their configuration changes. Backup and configuration history may be helpful during planned changes as post-change steps to quickly revert changes if something goes wrong. For more information on this feature, please visit our documentation page.

Conclusion

The TNSR CLI was designed to provide a user-friendly and industry-standard interface familiar to almost all network engineers. It has robust functionality to manage and show current device states. It’s easy to navigate the TNSR CLI and filter a specific configuration and show command outputs, allowing network engineers to troubleshoot quickly and effectively. We hope you find the TNSR CLI tips and commands in this article useful as you navigate and manage your TNSR router. Netgate will keep improving the CLI to give you a better user experience.