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?

0 points
Deleted by creator
permalink
report
reply
0 points

Add another DNS server (1.1.1.1, for instance) to your DHCP options. Your DHCP clients will use 1.1.1.1 when the pi-hole isn’t responsive.

permalink
report
reply
2 points

Does it really do that? I thought if pi-hole blocks it, it just says nothing here, normally a pc then looks up your secondary dns and then ads are back at it.

This was my experience when i did that.

permalink
report
parent
reply
8 points
*

Yes, your experience will be different if your DNS is being provided by another kind of DNS resolver. If you want a consistent pi-hole experience (and you can’t avoid downtime of your current pi-hole), add another pi-hole to your network and let that be your secondary DNS resolver.

permalink
report
parent
reply
3 points

No, that is not how DNS blocking works. It doesn’t just avoid responding, it responds but with a response that says that the domain does not exist or one that points to a different IP address.

permalink
report
parent
reply
7 points
*

Yeah this is the next best option, but a secondary pihole is the best, so you still get the dns blocking while the first one is down.

You listed cloudflare now (1.1.1.1) but I prefer https://www.quad9.net/ for the privacy and security.

permalink
report
parent
reply
19 points

I don’t think this accomplishes what he wants. The router DHCP will assign the second DNS address as you mention, but the devices will select one at random, not as a backup/failover. So what happens is that devices sometimes go through the Pi-hole and sometimes go through the secondary DNS address and receive ads. The only real way I’m aware of is to have a second pi-hole for redundancy. Personally, I decided to use a cloud based service (NextDNS) for this exact reason. I didn’t want my families internet to rely on devices that I host.

permalink
report
parent
reply
1 point

How many queries a month do you have? I’m at 15 days and I’m already at 750K. Do you pay for your service? I can do that, just curious what is common.

permalink
report
parent
reply
2 points
*

I’m at 30k blocked per day, over 100k queries per day.

This on a small 2 user network, with a handful of machines, but a fucking Samsung TV. That goddamn thing constantly pings all sorts of shit.

If I really restrict it (breaking some stuff on the TV), I can get to 35% of queries blocked per day, mostly from it.

Though nominal blocking kills the ads on the menu system, pretty well, making it much more responsive.

permalink
report
parent
reply
2 points
*

I’m not exactly sure how many queries, but it’s above the free limit. I purchased the pro plan. For $20 a year and it’s been a great service for me. I can send a referral code for 30% off (I think). I think adguard has a similar service.

permalink
report
parent
reply
1 point
*

I think it depends. In my limited experience, because I have not tested this thoroughly, most systems pick the first DNS adresses and only send requests to the second if first doesn’t respond.

This has lead at least a couple of times to extremely long timeouts making me think the system is unresponsive, especially with things like kerberos ssh login and such.

I personally set up my DHCP to provide pihole as primary, and my off site IPA master as secondary (so I still have internal split brain DNS working in case the entire VM host goes down).

Now I kinda want to test if that offsite DNS gets any requests in normal use. Maybe would explain some ad leaks on twitch.tv (likely twitch just using the same hosts for video and ads, but who knows).

Edit: If that is indeed the case, I’m not looking forward to maintaining another pihole offsite. Ehhh.

permalink
report
parent
reply
9 points

Wait, but then you cant tell if your device will use pihole even if its up. Afaik primary/secondary dns is not used in that order. I think best way is to set up 2nd pihole

permalink
report
parent
reply
27 points

They will also use 1.1.1.1 whenever they want. The order is not guaranteed.

Hosts also tend to use the same one for some time, so if your pihole went down clients may still favor 1.1.1.1 even after it comes back up.

permalink
report
parent
reply
5 points

I have my pi-hole setup as the upstream DNS in my router, with cloudflare as a secondary DNS. That way, all my devices always use the router for DNS (since that’s what is advertised in my DHCP) and the router then uses pi-hole if it’s available, or cloudflare if it isn’t. But the individual device doesn’t get to choose between different servers.

permalink
report
reply
8 points

The vast majority of devices that allow setting multiple DNS servers do not strictly prioritise one over the other even if they label it as primary and secondary.

permalink
report
parent
reply
2 points

That’s why I don’t let every device decide individually. I know my router (FritzBox) prioritizes the pi-hole (it’s even called “preferred” and “alternative” DNS-Server in the UI)

permalink
report
parent
reply
1 point

Those labels are quite common too with systems that do not prioritize one over the other.

permalink
report
parent
reply
9 points
*

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.

permalink
report
reply
1 point

Thanks, that might work. I’ll check into it.

permalink
report
parent
reply
59 points

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.

permalink
report
reply
31 points

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).

permalink
report
parent
reply
2 points

Could have pihole running on your desktop as a backup

permalink
report
parent
reply

Selfhosted

!selfhosted@lemmy.world

Create post

A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don’t control.

Rules:

  1. Be civil: we’re here to support and learn from one another. Insults won’t be tolerated. Flame wars are frowned upon.

  2. No spam posting.

  3. Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it’s not obvious why your post topic revolves around selfhosting, please include details to make it clear.

  4. Don’t duplicate the full text of your blog or github here. Just post the link for folks to click.

  5. Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).

  6. No trolling.

Resources:

Any issues on the community? Report it using the report flag.

Questions? DM the mods!

Community stats

  • 4.9K

    Monthly active users

  • 3.5K

    Posts

  • 75K

    Comments