DNAC is deploying old template settings to production switchs

[ChadHays98816]

DNAC Version 2.2.3.4

We have seen this in multiple locations on different switch stacks, random periods of time.   We deploy switch configurations using templates in DNAC, one of the settings is to configure two uplink ports as L3 routed with IP info, we then go back and  configure one of those of those as L2 with legacy vlan info depending on the site.   From time to time, we have a site lose all legacy connection, and find out the DNAC has converted that L2 uplink back to the original L3 settings and original IP info.    No clue what triggers it, but we have seen it over the past several months in different spots.   Any ideas how I can look at what might be triggering that, and prevent it?  It happened on a stack recently that has been in prod, and in DNAC for 6 months or longer.   Thanks in advance

[nirraman]

Hi,

The issue you're facing with DNAC converting the L2 uplink back to the original L3 settings and IP information could be caused by a few different factors. Here are some suggestions to help you investigate and potentially prevent this behavior:

1. Check for configuration drift: Verify if there are any processes or tools in your environment that may be automatically modifying configurations on the switch stacks. This could include scripts, configuration management tools, or other network automation systems. Make sure these tools are not inadvertently modifying the switch configurations.

2. Examine change logs: DNAC typically maintains logs of configuration changes made to network devices. Check the change logs to see if there are any entries related to the affected switch stacks and the specific L2 uplink configuration changes. This can help identify if any specific actions or triggers are causing the conversion.

3. Analyze DNAC templates: Review the templates used to deploy switch configurations in DNAC. Pay close attention to the sections related to the L2 uplink ports and their associated settings. Ensure that there are no conflicting configurations or misconfigurations in the templates that could trigger the conversion.

4. Monitor DNAC events and alarms: DNAC may provide event logs or alarms that can indicate any anomalies or unexpected behavior. Monitor these logs for any events related to the switch stacks experiencing the L2-to-L3 conversion. Look for any patterns or commonalities that might shed light on the trigger.

5. Check for software bugs or updates: Make sure that your DNAC software version (2.2.3.4) is up to date and check for any known issues or bugs related to the L2/L3 configuration management. Consult Cisco's support resources, release notes, and bug tracking databases to see if there are any relevant fixes or workarounds available.

6. Engage with vendor support: If you have exhausted your troubleshooting options and the issue persists, consider reaching out to Cisco support for assistance. They can provide further guidance, investigate the issue, and help you identify a resolution or workaround.

By following these steps, you should be able to gain insights into what might be triggering the L2-to-L3 conversion in DNAC and take appropriate actions to prevent it from occurring in the future.

If you find my reply solved your question or issue, kindly click the 'Accept as Solution' button and vote it as helpful.

You can also learn more about Cisco DNA Center through our live Ask the Experts (ATXs) session. Check out Cisco DNA Center ATXs Resources [https://community.cisco.com/t5/networking-knowledge-base/cisco-dna-center-ask-the-experts-resources/ta-p/4394489] to view the latest schedule for upcoming sessions, as well as the useful references, e.g. online guides, FAQs.

Regards,
Niranjana R