I have been seeing periodic drops in internet access from LAN connected devices lately (last 2 months), and I haven’t been able to figure about exactly what is going on. There doesn’t seem to be a pattern, and it resolves itself after a few hours.
- I can access the internet from my router
- All devices on LAN can reach each other, both wired and WiFi
- All devices on LAN can reach router, both wired and WiFi
- I haven’t changed anything in router settings
- I haven’t added new devices to my local network
- I can’t find any IP conflicts
- It’s a simple flat network with two APs, a single switch, no VLAN separation
tl;dr:
If you think something is blocking DNS traffic, you could try configuring DNS-over-HTTPs or DNS- over- TLS and picking a reputable upstream. This should obfuscate the traffic somewhat and get past common DNS interference issues and tactics.
So building on what yourself and everyone else has said, it does seem to be a DNS issue.
I found that at select times my local ISP was up to shenanigans with DNS.
I live in a very small country and work in IT. The NOC for all three ISPs and I have met. It would surprise me if they were competent enough to do this intentionally for malicious purposes.
If you can get access out to the internet via ping, see if you can do other things - get on a VPS and test with tcpdump at both ends. There’s a few free ones or trials great for disposable purposes like this. Set it up in advance…
You won’t know what it is til you troubleshoot.
I’ve had huawei firewalls reaching some simultaneous connection limit and fail, reversing their ruleset - blocking everything except ICMP, tr069 and ssh (concerning) outbound…
I’ve had problems with specific DNS servers, through the ISP’s network.
I’ve seen regular BGP changes causing outages all over the place (the ISPs locally don’t peer with each other…)
Post your findings, would love to help/hear!