https://devzone.nordicsemi.com/f/nordic-q-a/122090/zephyr-net-configHI， In the Zephyr config, these【NET_IPV6_NBR_CACHE &amp; NET_IPV6_ND】 are recommended to be enabled by default. Why does the Bulb project turn these off, and what impact will it have if they are turned off?en-USTelligent Community 13Fri, 06 Jun 2025 12:54:02 GMThttps://devzone.nordicsemi.com/thread/538421?ContentTypeID=1Fri, 06 Jun 2025 12:54:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ef4d5cd3-a39b-4d72-820e-876c8f943acdMarte Myrvold<p>Hi,</p> <p>These configurations are disabled when using Matter over Thread, as you can see here:&nbsp;<a href="https://github.com/nrfconnect/sdk-connectedhomeip/blob/b16d42678846cacd5ef9cadd01ceab00e2119bf6/config/nrfconnect/chip-module/Kconfig.defaults#L112">https://github.com/nrfconnect/sdk-connectedhomeip/blob/b16d42678846cacd5ef9cadd01ceab00e2119bf6/config/nrfconnect/chip-module/Kconfig.defaults#L112</a>.</p> <p>As stated in your picture, the config enables IPv6 neighbor cache. This is used for Ethernet and Wi-Fi, while Thread uses its own mechanism to handle neighbors, so the standard IPv6 neighbor cache mechanism is unnecessary when using Matter over Thread.</p> <p>Best regards,<br />Marte</p><div style="clear:both;"></div>