Up/down on TAP devices

[Ron Isaacson <isaacson ron gmail com>]

Hi there,

I'm using a VPN client which creates its own TAP device. It brings the
device up/down on connect/disconnect but doesn't handle DHCP or
routing. You're expected to start dhclient on your own once the device
is up.

I'd like NetworkManager to handle this. I managed to get the device
adopted with:

nmcli dev set vpn managed yes
nmcli connection add type tun ifname vpn con-name vpn mode tap

It immediately shows "connected" and starts dhclient. However, it
doesn't respond to the device going offline. If I stop the connection:

% ip link show vpn
5: vpn: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel state DOWN mode
DEFAULT group default qlen 1000

And yet:

% nmcli d show vpn
GENERAL.TYPE:                           tun
GENERAL.STATE:                          100 (connected)

And dhclient is still running, routes active, etc. Is there any way to
get NetworkManager to respond to state changes on the TAP device?

  - Ron