Homebridge NOT RESPONDING (after some time) - Fixed - Check your (Netgear) Switch!
Hey Homebridge Users,

**THIS ERROR CAN IMMEDIATELY BE MARKED AS FIXED**

I switched from a Raspberry Pi Zero (on Wifi) to a Raspberry Pi 4 on Ethernet and Restored my old configuration. All worked fine for serveral minutes and then devices started that "No Response" thing that everybody just hates. I disabled IPv6, Changed Avahi Settings, Changed Homebridge Versions, Changed Node Versions, Resetted Homebridge Completely ... nothing helped. I realized trough some troubleshooting that in the Bonjour Browser homebridge disappeared after some time ... and came back online ... and dissappeared. I read nearly all issues regarding "No Response" and someone (I don't find you anymore but thank you stranger) said that disabling "IGMP Snooping" in the Netgear Switch Settings helped to fix the problem. 

In the second I turned it off ALL devices came back online immediately. It was just like the TCP-Packets where waiting for that setting to be switched off 😄 

Sorry for creating a "new issue" but even if this Report gets closed instantly I hope I can help someone who is searching in the closed issues for the same problem because I don't want that anybody has to spend hours of debugging to find out that it is an issue with a network switch like me. Maybe someone could add a hint to the Wiki?

Just in the End: Thank you for Homebridge. I used it years ago but switched away very quickly because of reliability issues but 6 months ago I started using it again and if you exclude that little problem (which is not your fault) I had while switching I had not a single problem with homebridge and I enjoy using it everyday!

TL;DR If you have a Netgear switch and not responding devices disable "IGMP Snooping" in the switch settings it worked for me!
