DNS Client fails to support multiple nameservers

[owendelong]

In my environment, DHCPD provides two resolvers (192.159.10.2, 8.8.8.8). The first one is a closed resolver which provides an authoritative name server view to the internet and a resolver view to local clients. The second one is Google public resolver.

I had an outage with my name server yesterday during some maintenance to address a critical vulnerability in BIND. This was not an issue for most clients because they simply used the other name server. Unfortunately, my ESP8266 boards stopped submitting data during this time because they did not fall back to the other resolver.

You can see the results here: http://www.delong.com/cgi-bin/temp_combined.cgi Tuesday 8/4 17:00 to Wednesday 8/5 02:00.

The yellow and dark blue lines are collected by ESP8266. In contrast, the Red and Cyan lines are collected on Particle Photon platform.

[ESP_Faye]

Hi,

Could you please provide your test code ? We will have a try.

Thanks for your interest in ESP8266 !