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How to resolve NTP issue with Cisco Meraki Network

Last updated July 30, 2025

All Neat devices require NTP (Network Time Protocol) server for a variety of functions, and therefore a valid NTP server is a requirement when setting up and operating the devices. When troubleshooting, we find that blocked access to NTP server is one of the most common reasons that Neat devices cannot be successfully configured.

This article explains an interoperability issue between Cisco Meraki network and Neat devices that can lead to connectivity and operational issues with Neat.

Contents

1. DHCP option 42 support on Neat

When a Neat device is first connected to the network, it uses DHCP (Dynamic Host Configuration Protocol) to obtain its IP address and various other network details (gateway, DNS server etc.).

If a DHCP server provides a DHCP option 42 value during this process, Neat will exclusively use this as its NTP server and attempt to connect to it.

2. Issue specific to Cisco Meraki networks

Cisco Meraki networks have a known behaviour wherein, if no valid NTP server is configured by the network administrator, the Meraki Gateway populates the ‘DHCP option 42’ field with its own IP address. However, Meraki Gateway is not an NTP server and therefore it doesn’t respond to any NTP traffic. 

If a Neat device is configured in such a setup, it will pick up the DHCP option 42 as its NTP server (in this case, the Meraki Gateway) and start sending NTP requests to this IP address. However, since Meraki does not respond to these requests, Neat device thinks the NTP server is unavailable and in turn presumes its own status as offline (it will display the message ’Not connected to the internet’ or similar). 

3. How to resolve the issue

  • Configure a valid DHCP option 42 for the network (so that Meraki gateway does not try to populate this field with its own IP address).
  • OR, disable DHCP option 42 in the Meraki configuration (Neat will continue to use time.neat.no NTP server as its default). 

For general information about how to troubleshoot NTP issues, please go to the Check if NTP server is accessible article.