Fix Velop mesh flooding Pi-hole with PTR requests

[Bucking_Horn]

@chrislph

What is the default TTL for Pi-hole PTR responses? Is this updated using a dnsmasq config file?

Since Pi-hole FTL v5.10.1, Web v5.7 and Core v5.5 released Sep 2021, the default TTL for DNS records directly served by Pi-hole is 0 seconds for allowed and 2 seconds for blocked DNS requests:
(Note: TTL for records procured via Conditional Forwarding would be controlled by the target machine.)

@DL6ER

Handle TTL for blocked queries separately
You can now set your own local-ttl value if you want to.
Note that this changes the default TTL for local hostnames from two seconds to “do not cache” (dnsmasq’s default). If you want to avoid this, create a file like /etc/dnsmasq.d/99-local-ttl.conf and add a line like local-ttl=60 for one minute TTL on local hostnames.

Assuming the Velops would honor that TTL for their PTR requests, that would at least allow you to control the frequency of those requests.

I also vaguely recall a report from a user who were able to tackle this by switching DHCP duty from their Velop to Pi-hole. But that's probably not applicable to your setup with Velops operating behind a router.