[Swan] Dropping AUTH message containing INITIAL_CONTACT on OSX and Win10

[Derek Cameron]

I have found a solution to the problem of "missing payloads: AUTH" on
Windows 10 clients. It is necessary to first set up the VPN in the
Windows Settings GUI with VPN type of IKEv2. But then you must second
open a Windows PowerShell and issue the cmdlet:

Set-VpnConnection -Name "LibreSwan" -AuthenticationMethod "MachineCertificate"

The Windows 10 native client then connects to the CentOS 7 LibreSwan server.

But how do I get _all_ traffic from the Windows 10 client to be routed
through the LibreSwan server?

My /etc/ipsec.d/roadwarrior.conf looks like this:

conn roadwarrior
    left=123.23.23.23
    leftcert=123.23.23.23
    leftid=@123.23.23.23
    leftsendcert=always
    leftsubnet=0.0.0.0/0
    leftrsasigkey=%cert
    right=%any
    rightaddresspool=10.11.0.2-10.11.0.254
    rightca=%same
    rightrsasigkey=%cert
    modecfgdns="1.1.1.1,1.0.0.1"
    narrowing=yes
    dpddelay=30
    dpdtimeout=120
    dpdaction=clear
    auto=add
    ikev2=insist
    rekey=no
    fragmentation=yes
    ike=aes256-sha2_512;modp2048,aes128-sha2_512;modp2048,aes256-sha1;modp1024,aes128-sha1;modp1024