Been using the same simple server profile since 15.x.x on other hardware but just got this beast up and running after a few misfires. OpenVPN server won't start on the device. Again, exact duplicate configuration running on several hardware with various back-level releases.
Mon Oct 31 01:06:13 2022 daemon.warn openvpn(myvpn)[3203]: Cipher negotiation is disabled since neither P2MP client nor server mode is enabled
Mon Oct 31 01:06:13 2022 daemon.err openvpn(myvpn)[3203]: Options error: You must define TUN/TAP device (--dev)
Mon Oct 31 01:06:13 2022 daemon.warn openvpn(myvpn)[3203]: Use --help for more information.
config openvpn 'myvpn'
option enabled '1'
option verb '4'
option port '1194'
option proto 'udp'
option dev 'tun'
option server '10.8.0.0 255.255.255.0'
option ca '/etc/openvpn/ca.crt'
option cert '/etc/openvpn/cert.crt'
option key '/etc/openvpn/key.key'
option dh '/etc/openvpn/dh2048.pem'
option keepalive '10 120'
option status '/var/log/openvpn-status.log'
list push 'route 192.168.26.0 255.255.255.0'
list push 'redirect-gateway def1'
list push 'dhcp-option DNS 192.168.26.1'
Note: This is not a snapshot, not a vendor version but is from OpenWRT repository.