This one has me stumped.
Several apps on my phone are really slow to load content when connected to my home wifi:
- Twitter - tweets load fine, but images take an age (60 seconds plus) if they load at all
- RNZ stories do not load at all
- Spinoff stories do not load at all
But everything is fine on other apps, including Chrome and Gmail. Everything is also fine on notebooks (Windows and Chrome) connected to the same wifi network. Have also tested on other Android phones with the same issue. Progress! The issue seems to be something to do with particular Android apps.
Home setup is Voyager UFB with IPv6, to EdgeRouter Lite, to switch, to Cambium WAPs. I have several different WLANs with associated VLANs.
I have been testing with:
- VLAN 1, IPv6 on, Voyager DNS servers. No port 53 DNAT redirect
- VLAN 2, IPv6 on, non-Voyager DNS servers (PiHole + CleanBrowsing.org) + port 53 DNAT redirect
- VLAN 3, IPv6 off
No issues using VLAN3 with IPv6 off. Progress! It's something IPv6 related.
I switched from VLAN 1 to 2 (i.e. changed DNS servers). Twitter images immediately load. Progress! DNS seems likely to be to blame.
Or so I thought. Some time later, Twitter images don't load. Switch back from VLAN 2 to 1. Twitter images immediately load.
So things work, but toggling networks forces some kind of refresh to make them work properly? The way Android uses IPv6 DNS caches?
To paint a complete picture, I also recently moved from Vodafone to Voyager. No issues on Vodafone IPv6, this only cropped up after the shift to Voyager. And its too much for that to be coincidental. I reset the router when I changed so it has to be something to do with the way Android apps interact with:
- Voyager IPv6 - however I don't see why this would only affect Android apps and not anything else
- Something I've done setting up my router - this is much more likely
But I don't actually know what to do next. Is it even possible to do things like traceroutes on Android, pretending to be specific apps? Or is the culprit something I've done on the router and I should be looking there? But why only Android apps showing issues?
Appreciate any thoughts or suggestions for how to diagnose further.