The best practice of the openvpn is adding the two routes (0.0.0.0/1 and 128.0.0.0/1) to avoid replace the original default route. For this you can use the route options in the open vpn client configuration file: route 0.0.0.0 128.0.0.0 route 128.0.0.0 128.0.0.0
The Subnet Mask = 255.255.255.255 & Default Gateway = 0.0.0.0 are to be expected. That is what I see for my IKEv2 connection That basically says route all packets down the VPN tunnel - not split tunneling. Because your DNS server is 192.168.2.4, which presumably is behind your internal router - look at the router's settings 1st. solved: Double Connection with default gateway 0.0.0.0 Apr 19, 2010 How can I configure Advanced VPN settings? | SonicWall
Routing All Traffic Through a VPN Gateway on Linux
Vista: local only with 0.0.0.0 default gateway Jun 26, 2008
Dec 30, 2017
Dec 30, 2017 fix 0.0.0.0 default gateway - tweaking.com May 09, 2014