• 0 Posts
  • 25 Comments
Joined 1 month ago
cake
Cake day: September 20th, 2025

help-circle





  • Wait, both are DHCP providers? Admittedly, I haven’t looked too deep at pihole clusters - but do they synchronize their leases? If not, there’s a chance you might have duplicate IPs which can cause some interesting network behaviors.

    If your logs say both are having issues at the same time, I’d go with the second troubleshooting option - accept DHCP, but statically set DNS to the same servers your Piholes use.

    If there’s an issue, it’s with the upstream DNS (reachability or their rate limiting)


  • DNS isn’t instantaneous - and it’s hierarchical. If your systems are configured with pihole #1 (let’s say x.x.x.21) as primary and pihole #2 (x.x.x.22) for secondary and 21 fails, there will be a time when DNS requests time out. IIRC, for Linux it’s something like 4 seconds.

    I know this because I saw a really weird thing at a work lab where requests were taking 8 seconds to complete for all the internal sites, but internet sites worked immediately. Turns out two of three PDNS systems in our cluster weren’t configured properly for local lookup and systems would timeout on primary (+4 sec), timeout on secondary (+4 sec), then resolve with the tertiary server.

    I’m not saying that’s what’s happening here, but if this is a recent occurrence you could start with your primary/pihole and check system logs, updates etc. Or you could take a system that has this behavior and either swap the pihole order, and/or remove the pihole from the DNS all together to see if it’s even your gear causing the issue.