PiHole 5.1, CF, iOS devices oh me oh my

Please follow the below template, it will help us to help you!

Expected Behaviour:

As expected, pages should load

Actual Behaviour:

multiple pages, internal network and Internet won't load

Debug Token:

[Replace this text with the debug token provided from running pihole -d (or running the debug script through the web interface]

Network setup

Unifi Dream Machine with a /23 <--- yes, I really need this number of hosts!

Problem is that conditional forwarding will not let me specify a /23 CIDR. If I specify /16 the following happens:

I get hostnames instead of IP addresses as expected
on iOS devices, network connections (both via IP address and host names will often fail... giving server timeout issues.

If I disable CF, then everything works as expected, but I don't get host names through, which makes blocklist troubleshooting difficult.

I don't want to run the DHCP addressing off of the pihole as I much prefer the UDM interface for this.

Interesting results in testing. I sudo and edited the setupvars.cfg file and manually specified the values, including the /23 CIDR. While hostnames again populated the hosts instead of IPs, I immediately lost ability to DNS lookup across all my devices, including my Windows PC and streaming/casting devices (FireTV Stick and Apple TV).

As soon as I turned off conditional forwarding.. it all works again.

There's something screwy with conditional forwarding and I could use some help.

Dnsmasq (embedded in pihole-FTL) only supports octets for conditional forwarding, 8, 16, 24. Known issue. There is pending request for the dnsmasq devs to change this.

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See here how to manually set the configuration to split the /23 into two /24

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Thanks, good to know that there's a feature req. in for it. I thought I was going crazy as I would get intermittent functionality which made it a bugger to track down

Thanks. This is a good solution to my issue. Not ideal, but a workaround that is making things work until the root cause dnsmasq issue is patched. I wanted to do this for a smaller guest network (think /27) but I don't want to work upward from /32 (that's a LOT of rev-server commands given 2^5 yields 32!)

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