README v1.0.0 2025-02-03
Table of contents
1. General
1.1 Extract the NED package
1.2 Install the NED package
1.2.1 Local install
1.2.2 System install
1.3 Configure the NED in NSO
2. Optional debug and trace setup
3. Dependencies
4. Sample device configuration
5. Built in live-status actions
6. Built in live-status show
7. Limitations
8. How to report NED issues and feature requests
9. How to rebuild a NED
10. Configure the NED to use ssh multi factor authentication
11. The load-native-config feature
12. Handling default values1. General
This document describes the nec-ipasolink-vr NED.
Additional README files bundled with this NED package
Common NED Features
Verified target systems
1.1 Extract the NED package
It is assumed the NED package ncs-<NSO version>-nec-ipasolink-vr-<NED version>.signed.bin has already
been downloaded from software.cisco.com.
In this instruction the following example settings will be used:
NSO version: 6.0
NED version: 1.0.1
NED package downloaded to: /tmp/ned-package-store
Extract the NED package and verify its signature:
In case the signature can not be verified (for instance if no internet connection), do as below instead:
The result of the extraction shall be a tar.gz file with the same name as the .bin file:
1.2 Install the NED package
There are two alternative ways to install this NED package. Which one to use depends on how NSO itself is setup.
In the instructions below the following example settings will be used:
NSO version: 6.0
NED version: 1.0.1
NED download directory: /tmp/ned-package-store
NSO run time directory: ~/nso-lab-rundir
A prerequisite is to set the environment variable NSO_RUNDIR to point at the NSO run time directory:
1.2.1 Local install
This section describes how to install a NED package on a locally installed NSO (see "NSO Local Install" in the NSO Installation guide).
It is assumed the NED package has been been unpacked to a tar.gz file as described in 1.1.
Untar the tar.gz file. This creates a new sub-directory named:
nec-ipasolink-vr-<NED major digit>.<NED minor digit>:Install the NED into NSO, using the ncs-setup tool:
Open a NSO CLI session and load the new NED package like below:
Alternatively the tar.gz file can be installed directly into NSO. Then skip steps 1 and 2 and do like below instead:
Set the environment variable NED_ROOT_DIR to point at the NSO NED package:
1.2.2 System install
This section describes how to install a NED package on a system installed NSO (see "NSO System Install" in the NSO Installation Guide).
It is assumed the NED package has been been unpacked to a tar.gz file as described in 1.1.
Do a NSO backup before installing the new NED package:
Start a NSO CLI session and fetch the NED package:
Install the NED package (add the argument replace-existing if a previous version has been loaded):
Load the NED package
1.3 Configure the NED in NSO
This section describes the steps for configuring a device instance using the newly installed NED package.
Start a NSO CLI session:
Enter configuration mode:
Configure a new authentication group (my-group) to be used for this device:
Configure a new device instance (example: dev-1):
If configured protocol is ssh, do fetch the host keys now:
Finally commit the configuration
Verify configuration, using a sync-from.
If the sync-from was not successful, check the NED configuration again.
2. Optional debug and trace setup
It is often desirable to see details from when and how the NED interacts with the device(Example: troubleshooting)
This can be achieved by configuring NSO to generate a trace file for the NED. A trace file contains information about all interactions with the device. Messages sent and received as well as debug printouts, depending on the log level configured.
NSO creates one separate trace file for each device instance with tracing enabled. Stored in the following location:
$NSO_RUNDIR/logs/ned-nec-ipasolink-vr-cli-1.0-<device name>.trace
Do as follows to enable tracing in one specific device instance in NSO:
Start a NSO CLI session:
Enter configuration mode:
Enable trace raw:
Alternatively, tracing can be enabled globally affecting all configured device instances:
Configure the log level for printouts to the trace file:
Alternatively the log level can be set globally affecting all configured device instances using this NED package.
The log level 'info' is used by default and the 'debug' level is the most verbose.
IMPORTANT: Tracing shall be used with caution. This feature does increase the number of IPC messages sent between the NED and NSO. In some cases this can affect the performance in NSO. Hence, tracing should normally be disabled in production systems.
An alternative method for generating printouts from the NED is to enable the Java logging mechanism. This makes the NED print log messages to common NSO Java log file.
$NSO_RUNDIR/logs/ncs-java-vm.log
Do as follows to enable Java logging in the NED
Start a NSO CLI session:
Enter configuration mode:
Enable Java logging with level all from the NED package:
Configure the NED to log to the Java logger
Alternatively Java logging can be enabled globally affecting all configured device instances using this NED package.
IMPORTANT: Java logging does not use any IPC messages sent to NSO. Consequently, NSO performance is not affected. However, all log printouts from all log enabled devices are saved in one single file. This means that the usability is limited. Typically single device use cases etc.
3. Dependencies
This NED has the following host environment dependencies:
Java 1.8 (NSO version < 6.2)
Java 17 (NSO version >= 6.2)
Gnu Sed
Dependencies for NED recompile:
Apache Ant
Bash
Gnu Sort
Gnu awk
Grep
Python3 (with packages: re, sys, getopt, subprocess, argparse, os, glob)
4. Sample device configuration
Example:
See what you are about to commit:
Commit new configuration in a transaction:
Verify that NED is in-sync with the device:
Compare configuration between device and NED's CDB:
Note:
if no diff is shown, supported config is the same in NED's CDB(configuration database) as on the device.
On the device, the default values are not displayed. The NED mimics this behavior. However, if the user wants to check the default
values, then the following command can be used: admin@ncs(config-config)# show full | details.
To undo the previous modifications, the user can run the following command:
5. Built in live-status actions
exec any
The NED has support for all NEC VR4 and VR10 devices' operational mode commands. Use 'live-status exec any' command action to execute operation mode command.
Example:
6. Built in live-status show
NONE
7. Limitations
Due to the NSO behavior or YANG modelling restrictions, there are cases when the NED doesn't completely emulate the device's commands or behavior(like out-of-band changes).
Please find below such examples.
Example 1: On the device, the 'vlan entry 3500 "vlan test"' command looks different compared to the ncs_cli command: 'vlan entry 3500 name "vlan test"'.
When the command itself is sent to the device, the NED transforms the command in the right format, accepted by the device.
The reason why the command looks different in ncs_cli is to accomplish the device behavior.
The device accepts deleting the entire vlan list entry with 'no vlan entry 3500' command or deleting only the 'name' parameter(and keep the list
entry id) using the: no vlan entry 3500 name command.
Both deletion commands are supported by the NED:
Deleting the entire list entry:
or deleting the 'name':
When deleting the 'name', NSO considers this operation as a deletion of the entire list entry('entry' is a list) and a re-creation of the same entry, but without the 'name' element. This is why the 2 operations are visible above.
Example 2: On the device, the 'priority 0 scheduler dwrr 1' command, under the 'qos shaper queue-profile configuration 15' section, looks a little different compared to the equivalent command from the ncs_cli: 'priority 0 shaper scheduler dwrr 1'.
The NED automatically converts the 'priority 0 shaper scheduler dwrr 1' command to the correct format accepted by the VR devices. The reason for this slightly change is because the device displays the 'scheduler' parameter(at 'show running-config eth-function') the same way as it is configured in the ncs_cli.
8. How to report NED issues and feature requests
Issues like bugs and errors shall always be reported to the Cisco NSO NED team through the Cisco Support channel:
The following information is required for the Cisco NSO NED team to be able to investigate an issue:
Do as follows to gather the necessary information needed for your device, here named 'dev-1':
Enable full debug logging in the NED
Configure the NSO to generate a raw trace file from the NED
If the NED already had trace enabled, clear it in order to submit only relevant information
Do as follows for NSO 6.4 or newer:
Do as follows for older NSO versions:
Run a compare-config to populate the trace with initial device config
Reproduce the found issue using ncs_cli or your NSO service. Write down each necessary step in a reproduction report.
In addition to this, it helps if you can show how it should work by manually logging into the device using SSH/TELNET and type the relevant commands showing a successful operation.
Gather the reproduction report and a copy of the raw trace file containing data recorded when the issue happened.
Contact the Cisco support and request to open a case. Provide the gathered files together with access details for a device that can be used by the Cisco NSO NED when investigating the issue.
Requests for new features and extensions of the NED are handled by the Cisco NSO NED team when applicable. Such requests shall also go through the Cisco support channel.
The following information is required for feature requests and extensions:
Set the config on the real device including all existing dependent config and run sync-from to show it in the trace.
Run sync-from # devices device dev-1 sync-from
Attach the raw trace to the ticket
List the config you want implemented in the same syntax as shown on the device
SSH/TELNET access to a device that can be used by the Cisco NSO NED team for testing and verification of the new feature. This usually means that both read and write permissions are required. Pseudo access via tools like Webex, Zoom etc is not acceptable. However, it is ok with access through VPNs, jump servers etc as long as we can connect to the NED via SSH/TELNET.
9. How to rebuild a NED
To rebuild the NED do as follows:
When the NED has been successfully rebuilt, it is necessary to reload the package into NSO.
10. Configure the NED to use ssh multi factor authentication
This NED supports multi factor authentication (MFA) using the ssh authentication method 'keyboard-interactive'.
Some additional steps are required to enable the MFA support:
Verify that your NSO version supports MFA. This is configurable as additional settings in the authentication group used by the device instance.
Enter a NSO CLI and enter the following and do tab completion:
If 'mfa' is displayed in the output like above, NSO has MFA support enabled. In case MFA is not supported it is necessary to upgrade NSO before proceeding.
Implement the authenticator executable. The MFA feature relies on an external executable to take care of the client part of the multi factor authentication. The NED will automatically call this executable for each challenge presented by the ssh server and expects to get a proper response in return.
The executable can be a simple shell script or a program implemented in any programming language.
The required behaviour is like this:
read one line from stdin The line passed from the NED will be a semi colon separated string containing the following info:
The elements for device name, user, password and opaque corresponds to what has been configured in NSO. The ssh server name, instruction and prompt are given by the ssh server during the authentication step.
Each individual element in the semi colon separated list is Base64 encoded.
Extract the challenge based on the contents above.
Print a response matching the challenge to stdout and exit with code 0
In case a matching response can not be given do exit with code 2
Below is a simple example of an MFA authenticator implemented in Python3:
Configure the authentication group used by the device instance to enable MFA. There are two configurables available:
executable The path to the external multi factor authentication executable (mandatory).
opaque Opaque data that will passed as a cookie element to the executable (optional).
Try connecting to the device.
10.1 Trouble shooting
In case of connection problems the following steps can help for debugging:
Enable the NED trace in debug level:
Try connect again
Inspect the generated trace file.
Verify that the ssh client is using the external authenticator executable:
Verify that the executable is called with the challenges presented by the ssh server:
Check for any errors reported by the NED when calling the executable
11. The load-native-config feature
The nec-ipasoling-vr NED supports the load-native-config feature. The user can check if a specific configuration is supported or not by the NED. The load-native-config feature is used without a real connection towards the target device.
The user can choose to load the configuration by providing a configuration string or to load the configuration from a file. An important thing to take into account is that the configuration must be provided in the native format of the device. The current devices(VR4 and VR10) contain an '\r\n' at the end of each line and each configuration is found between the 'configuration' and 'exit' strings. Therefore, these must be provided by the user when the 'load-native-config' command is called.
Examples:
providing a string with device's native configuration
providing the configuration from a file
In the 'file-config.txt' file, the configuration can be copied directly from the target device, i.e. get the output after running the 'show running-config eth-function' command.
12. Handling default values
There are parameters with default values, which are not visible on the VR devices when set. Given the following example(only parameters of interest are displayed below):
Because the elements above are individual elements (and not components of list entries), to set them on the default, the user can set each of them with the associated default value or negate the command.
Set with default values:
Deleting the parameters:
In the end, the output will be the same.
On the other hand, if there are elements with default values and part of an list entry, the device will remove the entire list entry, when all the parameters are set on default. The expected output here(from NSO point of view), was to keep the list entry (with its id only) and remove all the other elements/leaves with default values.
Example: Lets's suppose the following configuration is present on the device:
If the user wants to set the 'priority 0' with the default elements as below:
The NSO expects to have the following configuration visible in NED's CDB:
But on the device, the 'priority 0' list entry is completely missing, which will trigger a compare-config diff.
As a workaround, to keep the sychronization between the NED's CDB and device, the user will have to issue a no command like this: 'no priority 0'.
A similar situation occurs in the 'qos shaper queue-profile configuration 15' case as well. Assuming this is the initial configuration:
If the user sets all the parameters above with default values:
Then, the entire list entry, 'qos shaper queue-profile configuration 15' will disappear from the device. On the other hand, on the NED side, the result will look like this:
To avoid the compare-config issue above, the user must use the following command: no qos shaper queue-profile configuration 15, instead of setting all the parameters with default values.
Another similar situation is the one described below: Given the following configuration:
If the user wants to set 'priority' to '0', he has to run the following command:
instead of:
which makes the entire entry to be deleted from the device.
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