I want to know the answer to the question, why does OpenVPN, when raised, send the default gateway settings not 0.0.0.0 but divides the gateway?

Question

openvpn

I want to know the answer to the question why OpenVPN, when raised, sends the default gateway settings not 0.0.0.0 but divides the gateway into two 128.0.0.1/1 and 0.0.0.0/1

Answer 1

Because the OpenVPN server has the redirect-gateway option specified with the def1 flag :
def1 -- Use this flag to override the default gateway by using 0.0.0.0/1 and 128.0.0.0/1 rather than 0.0.0.0/0. This has the benefit of overriding but not wiping out the original default gateway.
Using the def1 flag is highly recommended, and is currently planned to become the default by OpenVPN 2.1.

Answer 2

In order, for example, not to butt heads with other software that replaces the gateway (for example, the Cisco Anyconnect). And so - a more specific route will have a higher priority.