Pi-hole blocking internet access

[Ickleper]

@Bucking_Horn

Use a command like nslookup google.com 192.168.1.24 to establish whether Pi-hole would be able to resolve non-blocked queries through its public upstreams.

nslookup results:

C:>nslookup google.com 192.168.1.24
Server: raspberrypi.lan
Address: 192.168.1.24

Non-authoritative answer:
Name: google.com
Addresses: 2a00:1450:400b:c01::71
2a00:1450:400b:c01::65
2a00:1450:400b:c01::64
2a00:1450:400b:c01::8a
74.125.193.101
74.125.193.102
74.125.193.100
74.125.193.138
74.125.193.139
74.125.193.113

@Bucking_Horn

Then omit that IP and run all those nslookups from a client .
That will reveal what that client has used as DNS server for that request.

I'm assuming you meant Pi-hole IP (192.168.1.24). If so the results are as follows:

C:>nslookup google.com
Server: raspberrypi.lan
Address: 192.168.1.24

Non-authoritative answer:
Name: google.com
Addresses: 2a00:1450:400b:c01::8a
2a00:1450:400b:c01::64
2a00:1450:400b:c01::65
2a00:1450:400b:c01::71
74.125.193.113
74.125.193.139
74.125.193.138
74.125.193.100
74.125.193.102
74.125.193.101

C:>nslookup flurry.com
Server: raspberrypi.lan
Address: 192.168.1.24

Name: flurry.com
Addresses: ::
0.0.0.0

C:>nslookup pi.hole
Server: raspberrypi.lan
Address: 192.168.1.24

Name: pi.hole
Address: 192.168.1.24

@Bucking_Horn

If it's not (yet), then that client may have to acquire its DHCP lease through Pi-hole before it would start using Pi-hole for DNS.

I was using "ipconfig /release" and "ipconfig /renew" to ensure I was getting a new lease between config changes to the ISP router or the Pi-hole.

[Bucking_Horn]

Excellent!
Pi-hole knows its own name pi.hole (it's the only DNS server that does), blocks what it is supposed to block (flurry.com) and resolves what it should resolve (google.com), and all flawlessly without intermittent time-outs.

The trick was identifying that your router only allows configuring its upstream DNS, disabling its DHCP server and switching on Pi-hole's.

Looks like you have a working Pi-hole installation now.

[Ickleper]

Thanks a million for all your help, really appreciated!!!