====== Wired network fails after a while on the Pi 4 ======
  * **Symptoms:** \\ The Pi seemingly freezes up after about an hour (time varies), requiring hard reset.
  * **Reality:** \\ ''dhcpcd'' crashed/froze and didn't restart, and the network config got removed from the interface. \\ System can //temporarily// be recovered by statically assigning ip & route, or by running ''systemctl restart dhcpcd'' in a serial terminal or with a directly connected keyboard and mouse.
  * **Workaround:** \\ Add the following to ''/etc/dhcpcd.conf'': <code properties>
# https://github.com/raspberrypi/linux/issues/4092/
denyinterfaces veth*
</code>
  * [[https://github.com/raspberrypi/linux/issues/4092/|Raspberry Pi 4: DHCPCD route socket overflowed]]
  * Also tracked by Jeff Geerling: [[https://github.com/geerlingguy/internet-pi/issues/611|Pi drops IPv4 address after DHCP lease expires]]