The OpenVPN 2.6.15 release brings back support for explicitly configuring the broadcast address on Linux systems, on interfaces where applicable. This feature was removed from the OpenVPN 2.6 series because “computers are smart and can do it themselves”.
Source: https://9to5linux.com/openvpn-2-6-1...-explicitly-configuring-the-broadcast-address
Source: https://9to5linux.com/openvpn-2-6-1...-explicitly-configuring-the-broadcast-address

