Hi. I'm trying to help my girlfriends dad set up a RPi3B running MotionEyeOS to watch his outdoor fish tanks. This will probably be more of a general networking question rather than something RPi or MotionEyeOS specific.
The wireless connected RPi stops responding to inbound connection attempts (ssh / http / ping) after a period of time. The strange part is that it starts working again if I open the shell on the RPi and ping the remote host first.
For example, if the remote host is "A" and the RPi is "B" then "ping B" from A will fail. If I "ping A" from "B" first it will work (although there will be a couple lost packets to begin with). Following that "ping B" from A will be successful for a while after. Pinging the router was not sufficient. It had to be the host that I was trying to communicate with (my phone / laptop / or both).
Strangely each host has this issue. If I introduce a "C" node, it won't work until I do the same thing as above, even if A<-->B are already working.
The modem / router is in another house, connected via a wired ethernet connection to this house into a wireless access point, and finally to the RPi. There is only one subnet that all the hosts are on.
I can't change the network setup too much because 1) the router admin pages are all in Japanese and I can't read them. 2) If things break, I won't be here to fix them.
I guess I'm hoping someone might have an idea about what might be going wrong since I'm pretty well stumped. It is like the wireless connection is going to sleep, but I don't think that is the case. My best bet is that it is something to do with the main router (arp cache or something)?