I have a vpn server which seems to be working fine with about a dozen macs, a couple of windows laptops and several ubuntu laptops usually connected. Only one machine, a MacBook Pro which belongs to the CEO, has persistent and intermittent black screen problems.
The connections seems to work fine most of the time but once or twice a day the vpn session will freeze and clicking disconnect causes a black screen crash. This happens when using either Tunnelblick or Viscosity. I can't find any reports of similar issues on the net and hoping somebody here can give me a few clues.
OpenVPN 2.4.4, OpenSSL 1.0.2n, running on Ubuntu 16.04 server.
Here is my server config
dev tun
proto Udo
port 1194
ca /path/to/ca.crt
cert /path/to/server.crt
key /path/to/server.key
server 10.3.255.0 255.255.255.0
ifconfig-pool-persist ipp.txt
ncp-disable
cipher AES-256-GCM
auth SHA512
tls-version-min 1.2
tls-cipher TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384
dh none
ecdh-curve secp521r1
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.4.4"
push "route 10.0.0.0 255.0.0.0"
keepalive 10 120
persist-key
persist-tun
tls-server
tls-crypt /etc/openvpn/server/tls-auth.key
crl-verify /path/to/crl.pem
status /var/log/openvpn-status.log
log /var/log/openvpn.log
user ovpn
group ovpn
verb 3
daemon
Here is my client config
client
proto udp
dev tun
persist-key
persist-tun
remote vpn.myhost.com 1194
resolv-retry infinite
nobind
explicit-exit-notify 1
remote-cert-tls server
auth SHA512
cipher AES-256-GCM
tls-version-min 1.2
tls-client
ping 15
ping-restart 120
<ca>
...
</ca>
<cert>
...
</cert>
<key>
...
</key>
<tls-crypt>
...
</tls-crypt>
