My Pi3 running Jessie loses connectivity after unplugging and plugging back the ethernet cable. It's literally driving me crazy. Hope you could shed some light here.
Wifi is disabled in /boot/config and raspi-blacklist.
/etc/network/interfaces is as follows:
# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
auto eth0
allow-hotplug eth0
iface eth0 inet manual
#allow-hotplug wlan0
#iface wlan0 inet dhcp
# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
#allow-hotplug wlan1
#iface wlan1 inet manual
# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
Thank you
ifup eth0
? – Radu Jan 23 '18 at 00:43dhcp
which is invalid. This may be related to your problem. See How to set up networking/WiFi – Milliways Jan 23 '18 at 00:52