I have an asus router with a pi-hole on the network.
I was doing some work on my server and noticed that when pi-hole was down, I couldn’t access the internet. I was looking for some ideas online how to deal with this, but they said to have a second pihole on the network in case one is offline. Is that the only way to do it? Is there any way to have the network go back to normal if the pihole is offline?
I was doing some work on my server and noticed that when pi-hole was down, I couldn’t access the internet.
You’ve opted to take control over a critical piece of network infrastructure. This is to be expected.
There’s a reason DHCP provides for multiple DNS servers to be listed. Having redundant DNS servers is a common setup. So yes, multiple piholes if you want stability.
Just wanted to add onto your comment for clarity for others, the multiple servers are not redundancy so much as first come first serve, which is why your comment of multiple pi-holes is important.
If you were to list a pihole and say Google DNS as primary and secondary respectively, you may have some DNS queries responded to by Google. Negating the point of having a pi-hole or similar DNS service locally.
A secondary can be a docker container, another physical pi-hole (even a zero-w, which I personally don’t recommend being your only way to manage DNS, but is fine when you just need to do some maintenance on the primary).
One option is just do a temporary change on your PC to different DNS servers while you work on the stuff.
Otherwise a second PiHole set as the secondary DNS in DHCP would keep things online.
Otherwise a second PiHole set as the secondary DNS in DHCP would keep things online.
No, that just creates time outs and delays when either of them is offline.
The proper way is to have a standby pihole that takes over the IP address of the main pihole when it goes down. It’s quite easy to achieve this with keepalived.
Not sure if this is common knowledge but Pi-hole can also run in a docker container, it doesn’t have to be a raspberry pi. I have it running on portainer on two different machine in my house. I’m a systems architect by trade so there no kill like overkill 😅
You might be a nerd when you have to schedule maintenance at your own house.
one a VM, the other a container, with different upstream targets. I have to schedule maintenance when everyone is asleep or out of the house. I’ll swear one day I’ll have a proper (raspberry pi) cluster with KVM, I just need to finish implementing the other million things I find when I research it.
Another trick is setting up a guest/secondary AP that don’t use pi-hole. When your pihole is down, just switch to the secondary AP. Most routers can setup multiple APs, though not all can setup different dns server for the other APs.
On Mikrotik I have a script that runs every 30sec. If pi-hole not responding, router switches to public cloudflare dns records, otherwise to pi-hole IP.
This setup works like a charm.
P.S. I am using Blocky, but it’s almost the same as Pi-Hole.
EDIT: Since at least 2 guys asked how to do it:
https://forum.mikrotik.com/viewtopic.php?p=866934#p866934
Don’t forget to configure Mikrotik router to act as passthrough DNS server with cache (for performance) and configure DHCP server’s DNS to router’s IP.
That sounds cool. I’ve never messed with scripts on Mikrotik, but would it be possible to share what you have?
I’m guessing a relatively short DHCP lease time is also in play so devices can get the new DNS address? Or do you have Mikrotik set as the DNS server?
Seconding the request to share your work.
That is an amazing idea you’ve come up with that I never considered, but now I need it.
