$ openvpn --config server.conf
# ...
# Initialization Sequence Completed

$ ifconfig
tap0: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>  mtu 1500
        inet6 fe80::d8a9:b7ff:fe14:6d3e  prefixlen 64  scopeid 0x20<link>
        ether da:a9:b7:14:6d:3e  txqueuelen 100  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 27  bytes 2210 (2.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0