PiHole 5.1, CF, iOS devices oh me oh my

[webster83]

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 10.0.0.0 /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.

[webster83]

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.

[jfb]

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.

[yubiuser]

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

Support prefix /12 for conditonal forwarding

I have come across this same issue. From reading through various posts this is a limitation of DNSMASQ, but it appears there is a way around this by entering something like CharAznable's set of 'rev-server=' lines rather than using the web GUI. I think it would be good to have a post that details actually what needs to be done to get conditional forwarding working on non standard subnets. Anyone want to contribute to this with corrections or ideas? WORK IN PROGRESS, NOT GUARANTEED TO WORK -…

[webster83]

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

[webster83]

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!)