Make a Pi-Hole Work with a Bell Giga Hub

Due to a recent 10-block move there were shenanigans and my previous ISP was incapable of transferring my service to our new address. As a result, I signed up for the much faster Bell Fibe, fibre-to-the-home service. Now I have a 1.5 Gigabit internet connection, and pay less than I did for the 25 megabit connection. Sweet! I had some trouble getting my Pi-Hole up & running so I’m sharing what I did in case others have similar problems.

The Previous Setup

My old setup consisted of a DSL modem in bridge mode and an TP-Link Archer C7 router V2 that handled all networking tasks except for responding to DNS queries. The C7’s DHCP settings pointed to the Pi-Hole as the main DNS server for the network, and it worked great.

The Plan: Giga Hub + Pi-Hole

Included with my new service is a Bell Giga Hub, which is a combination ONT and router, (with a 10 gigabit ethernet port and wifi 6e!). Despite some complaints in /r/bell it seems like a very capable device, so I planned to use it as the main network device, and try to use it to point all devices on the network to a Raspberry Pi running Pi-Hole.

The Roadblock

Despite a place in the Giga Hub’s admin interface where it looks like I should be able to point the DNS at the Pi-Hole, I couldn’t get it to work. Every time I pointed DNS at the Pi-Hole the Pi-Hole couldn’t access the internet. It couldn’t even ping an IP address.

A screenshot of the Bell Giga Hub's dns settings
It looks like I should be able to set a DNS server here… but it doesn’t work.

Side Quest: Restoring Internet Access to the Pi-Hole

I ended up with a Raspberry Pi that couldn’t access the internet, which wasn’t ideal. The Pi was accessible on the local network, so I initially restored its internet access by changing it’s IP address. I later realized that turning setting the Giga Hub’s DNS back to “Obtain DNS information automatically” and changing or deleting the IP address in the “Manually specify DNS information” would restore the Pi’s internet access. It seemed that even though the router was using external, upstream, DNS, it was still doing something weird with the IP address in the inactive “Manually specify DNS information” screen.

DHCP to the Rescue

The solution ended up being relatively simply. Pi-Hole has the option to use the Pi-Hole as a DHCP server, and it is smart enough to tell connecting devices to also use the Pi-Hole for DNS. So I turned on the Pi-Hole’s DHCP server and configured it to allocate IP addresses in the same range as the Giga Hub, then turned off the DHCP server on the Giga Hub and everything worked. DHCP is a broadcast service so there is no configuration telling clients where to find the server. If there’s a DHCP server on the network the devices will find it.

Some posts in /r/bell had me worried that I would have to either use my C7 or another, faster, router in PPPoE mode, but switching to the Pi-Hole as the DHCP server was enough. That’s great because I didn’t want to buy another fast router, or use my older C7 when there’s a perfectly capable Wifi 6e router in the Giga Hub.

When I set this all up my Giga Hub was on Firmware version 1.14.something. The firmware was recently updated to version 1.16 and is still working. It may be that Firmware 1.16 also fixes the problem I had setting the DNS server on the Giga Hub, but what I have is working, and if it ain’t broke don’t fix it.

A screenshot of my pi hole admin panel showing that it is processing thousands of DNS queries.
My Pi-Hole is processing thousands of DNS queries, (yes, I know blocking is off at the moment).