Arch Linux

-thc

Member

Registered: 2017-03-15

Posts: 496

[Solved] Networkmanager-Openvpn sometimes creates "zombie" connections

After upgrading "networkmanager-openvpn" from 1.8.1dev+9+gf9e2fd5-1 to 1.8.2-1 on Arch x64 I noticed this strange behavior:

1. Booting Arch and starting a single bridged OpenVPN connection works as expected.
2. Disconnecting the connection seems to work (routes are deleted, network is no longer reachable) but the OpenVPN process stays active.
3. Every 120 seconds the journal shows the "zombie" VPN connection getting restarted due to inactivity (still claiming the original tunnel device "tap0")

4a. Starting the same VPN connection again works (nm-openvpn now using "tap1"), but for 120 seconds maximum. When the "zombie" connection restarts, the second connection no longer works (routes with tap1 are still present, network is no longer reachable)
5a. Disconnecting the second connection leads to another "zombie" connection.

4b. Starting the same VPN connection again doesn't work (nm-openvpn starting a second OpenVPN process using "tap1"). nm-openvpn tries unsuccessfully to re-use the old connection and fails. The NetworkManager Applet gets confused.

This is not reliably reproducible. Sometimes disconnecting works five times in a row and sometimes the first disconnect fails.
Compared to the normal behavior the journal doesn't reveal anything out of the ordinary.

Tunneled VPNs (tunX) seem to be completely unaffected.

Workarounds: Reboot after unsuccessful disconnects or downgrade to 1.8.1dev+9+gf9e2fd5-1

Last edited by -thc (2018-05-30 06:35:45)

-thc

Member

Registered: 2017-03-15

Posts: 496

Re: [Solved] Networkmanager-Openvpn sometimes creates "zombie" connections

This issue is resolved with networkmanager-openvpn 1.8.4.