Here we go again. This time, the script revealed nothing that looked interesting. Here are some extracts from logs:- 2017-09-28T02:52:32+0100 ifconfig ================================== eth0 Link encap:Ethernet HWaddr 00:25:64:72:72:14 inet6 addr: fe80::c1e6:4b25:5c64:f669/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7627566 errors:0 dropped:0 overruns:0 frame:0 TX packets:2808062 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2606664279 (2.6 GB) TX bytes:18724680986 (18.7 GB) Interrupt:18 ... 2017-09-28T02:52:32+0100 ls -lA /var/run/dhclient* ================================================== -rw-r--r-- 1 root root 6 Sep 28 02:47 /var/run/dhclient-eth0.pid -rw-r--r-- 1 root root 6 Sep 27 14:28 /var/run/dhclient.pid ---------------- 2017-09-28T02:52:32+0100 ps aux | grep -v grep | grep dhc ========================================================= root 30610 0.0 0.0 16128 1540 ? S Sep27 0:00 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /var/run/dhclient-eth0.pid -lf /var/lib/NetworkManager/dhclient-3339a4b3-ef0a-3db1-acf1-9b810d040dfe-eth0.lease -cf /var/lib/NetworkManager/dhclient-eth0.conf eth0 ---------------- Attempting to wake inactive interfaces (which had seemed to work previously) did not revive a connection, but there was success when trying to revive the interface that should have been active (although it was not the expected address), then another restart brought things back to the norm:- [LinuxMint] graham@yoyo $ TestNet.sh Starting /home/graham/bin/TestNet.sh, version : 0.9 $. No default route has been detected. Our I.P. address : Finished /home/graham/bin/TestNet.sh. Thu Sep 28 03:18:14 ~ [LinuxMint] graham@yoyo $ export ifc="eth0" ; sudo ifconfig -v ${ifc} down ; sleep 3 ; sudo ifconfig -v ${ifc} up ; sleep 2 ; sudo /sbin/dhclient -v ${ifc} ; ifconfig ${ifc} Internet Systems Consortium DHCP Client 4.3.3 Copyright 2004-2015 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/00:25:64:72:72:14 Sending on LPF/eth0/00:25:64:72:72:14 Sending on Socket/fallback DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x6719e377) DHCPREQUEST of 192.168.42.224 on eth0 to 255.255.255.255 port 67 (xid=0x77e31967) DHCPOFFER of 192.168.42.224 from 192.168.42.129 DHCPACK of 192.168.42.224 from 192.168.42.129 bound to 192.168.42.224 -- renewal in 741 seconds. eth0 Link encap:Ethernet HWaddr 00:25:64:72:72:14 inet addr:192.168.42.224 Bcast:192.168.42.255 Mask:255.255.255.128 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7629942 errors:0 dropped:0 overruns:0 frame:0 TX packets:2812141 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2606838298 (2.6 GB) TX bytes:18725038253 (18.7 GB) Interrupt:18 Thu Sep 28 03:19:14 ~ [LinuxMint] graham@yoyo $ TestNet.sh Starting /home/graham/bin/TestNet.sh, version : 0.9 $. Our I.P. address : 192.168.42.224 Gateway : 192.168.42.129 Gateway interface : eth0 Looking for an Internet connection ... Can we contact a remote computer by name using "ping"? Trying www.google.co.uk ... Found www.google.co.uk - an Internet connection probably exists. No problem found. Finished /home/graham/bin/TestNet.sh. Thu Sep 28 03:19:31 ~ [LinuxMint] graham@yoyo $ export ifc="eth0" ; sudo ifconfig -v ${ifc} down ; sleep 3 ; sudo ifconfig -v ${ifc} up ; sleep 2 ; sudo /sbin/dhclient -v ${ifc} ; ifconfig ${ifc} Internet Systems Consortium DHCP Client 4.3.3 Copyright 2004-2015 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/00:25:64:72:72:14 Sending on LPF/eth0/00:25:64:72:72:14 Sending on Socket/fallback DHCPREQUEST of 192.168.42.224 on eth0 to 255.255.255.255 port 67 (xid=0x4ddc7c5b) DHCPACK of 192.168.42.224 from 192.168.42.129 bound to 192.168.42.224 -- renewal in 859 seconds. eth0 Link encap:Ethernet HWaddr 00:25:64:72:72:14 inet addr:192.168.42.224 Bcast:192.168.42.255 Mask:255.255.255.128 inet6 addr: fe80::c1e6:4b25:5c64:f669/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7630498 errors:0 dropped:0 overruns:0 frame:0 TX packets:2812743 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2607038590 (2.6 GB) TX bytes:18725167768 (18.7 GB) Interrupt:18 Thu Sep 28 03:19:41 ~ [LinuxMint] graham@yoyo $ ip address show eth0 2: eth0: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 00:25:64:72:72:14 brd ff:ff:ff:ff:ff:ff inet 192.168.42.187/25 brd 192.168.42.255 scope global dynamic eth0 valid_lft 1400sec preferred_lft 1400sec inet6 fe80::c1e6:4b25:5c64:f669/64 scope link valid_lft forever preferred_lft forever Thu Sep 28 03:20:37 ~ [LinuxMint] graham@yoyo $ TestNet.sh Starting /home/graham/bin/TestNet.sh, version : 0.9 $. Our I.P. address : 192.168.42.187 Gateway : 192.168.42.129 Gateway interface : eth0 Looking for an Internet connection ... Can we contact a remote computer by name using "ping"? Trying www.google.co.uk ... Found www.google.co.uk - an Internet connection probably exists. No problem found. Finished /home/graham/bin/TestNet.sh. Thu Sep 28 03:39:40 ~