我知道这个问题不是很复杂，但是我在互联网上没有遇到任何解释，这就是为什么我认为这个答案会有所帮助这就是为什么我写它而不是删除我的最初问题。

I know that question is not very complex, but I didn't encounter any explanation in the internet, this is why I think this answer would be helpful and this is why I'm writing it instead of deleting my initial question.

您只需指定更多参数以使其起作用

You just should specify more parameters to make it work

    var route = new MIB_IPFORWARDROW
                {
                    dwForwardDest = BitConverter.ToUInt32(IPAddress.Parse("XX.XX.XX.XX").GetAddressBytes(), 0),
                    dwForwardMask = BitConverter.ToUInt32(IPAddress.Parse("255.255.255.255").GetAddressBytes(), 0),
                    dwForwardNextHop = BitConverter.ToUInt32(IPAddress.Parse("XXX.XXX.XXX.XXX").GetAddressBytes(), 0),
                    dwForwardMetric1 = 99,
                    dwForwardType =  ForwardType.Indirect,
                    dwForwardProto =  ForwardProtocol.NetMGMT,
                    dwForwardAge = 0,
                    dwForwardIfIndex = interfaceIndex
                };
    var ipForwardEntry = RouteInterop.CreateIpForwardEntry(ref route);