Primary DNS Alternatives
Primary DNS Alternatives
I configured two piholes with one primary and one secondary DNS. I thought the secondary would only handle a small portion of traffic, but the load is higher than expected. It receives about one-twentieth of what the main DNS gets. The decision on which DNS to use depends on when the primary fails, not necessarily on a specific event.
Could it mean the system will automatically redirect to the third or default DNS if the secondary one also fails?
Based on the speed of your hardware, Pi-holes might lag when handling many queries at once, which is why it sometimes checks the second one. This could happen, but logs would confirm. If only a small fraction of traffic comes through, the third one is unlikely to be used, though it's not impossible.
Varies by user. Devices like Roku boxes attempt to handle DNS via any known settings in a round-robin fashion. Most PC clients rely on them for orderly access. Pihole maintains logs detailing which domains are requested, the records accessed, and the return logs available through its web interface.
Based on the Pi-Hole version it's using, a second unit isn't really necessary. I manage a large network with 36 clients—including personal devices and servers, plus many more during events. My setup runs on a single RPi 3B+ with Pi-Hole, and it's performing well without any issues. Unless you're in a big enterprise setup, I wouldn't need two devices.