Weird Network Issues
Reading time: 2 minutes (295 words)Author: @pugmiester
Tags: network , ipv6 , dns
We’ve had some, best described as “odd”, network glitches at home over the last few days but I couldn’t quite put my finger on it. Our Google home devices would barf when asking them to set alarms and they also fail to play back any of the text to speech messages from Home Assistant. The Xbox reported only legacy IP connectivity and no IPv6. Client devices were sluggish loading websites and apps. Nothing looked obviously wrong, it just didn’t feel right.
Well dear reader, I can confirm it was…… drum roll please…. DNS (It’s always DNS) well sort of.
What I hadn’t noticed was that BT, our ISP, had decided to issue us with a new IPv6 prefix a few days ago. All of the VLAN’s have an IPv6 DNS server listed that points to pihole, or it used to. Because of the prefix change, pihole had a new IP so all of the IPv6 DNS request were landing on deaf ears leading to general weirdness for all sorts of devices.
I’ve updated the DNS details in the router advertisments on my pfSense firewall and things seem to be catching up again. The Xbox is now connecting with both IPv6 and legacy IP. Website and app load times are back to being snappy and reliable. I’ve not checked the Google home devices yet but I’m sure this is the likely cause for their problematic bahaviour as well.
So, as always, “It’s always DNS, and IPv6”.
One of these days I’ll get my arse in gear and move ISP’s to one that provides a fixed IPv6 prefix, something I talked about here previously. It’s still on my todo list, but so are a lot of other thangs, some of which are blockers for the ISP change.