How to get IPs/hostname from clients from different network(s)?

[deHakkelaar]

@yubiuser

You might need to change your setup and assign IPs for each subnet to your Pi-hole device. Something like

Assign multiple IP addresses to single Network card in Linux

This comprehensive tutorial describes how to assign multiple IP addresses to single Network card in Linux operating systems.

Est. reading time: 9 minutes

Above guide configures IP's in /etc/network/interfaces that most likely will conflict with dhcpcd5 thats installed:

pi@ph5:~ $ journalctl -u dhcpcd
[..]
Jan 25 21:20:34 ph5 dhcpcd[7767]: eth0: using static address 10.0.0.4/24
Jan 25 21:20:34 ph5 dhcpcd[7767]: eth0: adding route to 10.0.0.0/24
Jan 25 21:20:34 ph5 dhcpcd[7767]: eth0: adding default route via 10.0.0.1
[..]

Below better to assign multiple IP's to a single interface:

Pi-Hole VLAN advice using 05-custom.conf or define VLAN interfaces

Vlan's are a switch thing. Clients and servers dont need to be aware what vlan's they are in. They only need to be aware of the subnets. There are some exceptions like hypervisors that apply virtual bridges etc for their guests/VM's that need to be in vlan trunks. I could be wrong missing some bits but am sure someone here will correct me To prevent having to route traffic between the subnets, you could assign all appropriate vlan's to the switch/router port that Pi-hole is connected…