Xenialpup 7.5 (32bit with Kernel 4.4.95)
Sometimes my internet connection goes away (http, SSH, and ping all time out, even to numerical addresses both internet and local) but "Network Information" and the ip a command shows the same info as when it was working and the task bar still show the "connected" ikon.
Disconnecting (from task bar) & using Network Wizard to re-establish show "connected" again, but doesn't fix it; a reboot always works.
The actual connection, which always works initially, is eth0 with a Static IP (set manually to an address on 192.168.86.x, with gateway of 192.168.86.1) connected to a Win10 Network Bridge connected by 5GHz WiFi to a Google Mesh local network. (DHCP does not work for this configuration. Google prefers a DNS primary of 192.168.86.1 but it works with 8.8.8.8 etc; DNS is not an issue because the problem exists for IPv4 numerical addresses.)
This problem seems to occur after visiting web sites with hostile/unsupported scripts but not immediately enough to pin down which ones, sometimes within 5 minutes but sometimes after 6+ hours. Can't find my notes on the site which brought it down within 5 minutes; otherwise, using mostly reliable sites like en.wikipedia.com/wiki/. Not completely sure, but I think if no internet connection is used even after 8+ hours, then a new connection will always work. (There is some evidence that the 4.4.95 kernel may corrupt memory after a long time on this Toshiba Satellite A105.)
My question is, what tools or procedures could to used to determine what the actual network problem is?