"service networking restart" , attempts to reconnect, usually failing because the usb cable needs to be detached several times before a reconnect, sometimes rebooting works, but always a manual cable reconnect is required.

Note that the networking service controls ifupdown (/etc/network/interfaces{,.d/*}) and so should not affect connman.

ip link gives

glenn@asus-r552jv:~$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether 40:16:7e:00:db:32 brd ff:ff:ff:ff:ff:ff
3: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
    link/ether 24:0a:64:64:39:c5 brd ff:ff:ff:ff:ff:ff
4: eth1: <BROADCAST,MULTICAST,DYNAMIC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/ether 96:ea:32:35:c6:55 brd ff:ff:ff:ff:ff:ff
glenn@asus-r552jv:~$ 

"service dbus restart" , works but disconnects the network first, then I have to struggle (multiple tries) to reconnect tethering.

"service networking restart" , attempts to reconnect, usually failing because the usb cable needs to be detached several times before a reconnect, sometimes rebooting works, but always a manual cable reconnect is required.

Thank you for your consideration...

edit > "service connman start" seems to help.

p.s. Would this be a good way to restart connman?

/etc/init.d/connman restart

From other distros I'm used to starting and stopping daemons that way, the service command is new to me.

$ ip link

It's possible that restarting dbus would have worked, although historically I never got a dbus restart to actually operate correctly (on CentOS, but same bucket of poison, eh).

sudo service dbus restart

Although in Debian-based distros like our beloved Devuan, perhaps this would work:

sudo service networking restart

glenn@asus-r552jv:~$ connmanctl technologies
/net/connman/technology/ethernet
  Name = Wired
  Type = ethernet
  Powered = True
  Connected = True
  Tethering = False
/net/connman/technology/bluetooth
  Name = Bluetooth
  Type = bluetooth
  Powered = False
  Connected = False
  Tethering = False
/net/connman/technology/wifi
  Name = WiFi
  Type = wifi
  Powered = True
  Connected = False
  Tethering = False
glenn@asus-r552jv:~$ 

Although I have no wifi devices listed in the networking app in the taskbar.

I have been watching to see if there was something I have done to disable the wifi, bluetooth seems to work, but I haven't found a use for it.

Currently, I'm using ipheth tethering from my phone, which works while I'm not at home but it a bit of a pain to get going.

I'm following with interest. Thank you for the tips.

So today connman (a network manager) failed in a strange and new way. I lost net (nothing strange in that).  Then it got strange.  The icon in the tool tray brought up an empty window instead of the usual list of network interfaces. it was as if someone has opened up my computer and removed all network cards.

Then I decided to see what was up from the console:

root@moonshadow:~ # connmanctl technologies
Error: The name net.connman was not provided by any .service files
root@moonshadow:~ #

Rebooted.  Got net, yay.
For comparison, here is some normal output from connmanctl:

bob@moonshadow:~ $ connmanctl technologies
/net/connman/technology/p2p
  Name = P2P
  Type = p2p
  Powered = False
  Connected = False
  Tethering = False
/net/connman/technology/ethernet
  Name = Wired
  Type = ethernet
  Powered = True
  Connected = False
  Tethering = False
/net/connman/technology/wifi
  Name = WiFi
  Type = wifi
  Powered = True
  Connected = True
  Tethering = False
bob@moonshadow:~ $

question
Has anyone else had this happen?