chromium/chromeos/components/test/data/onc/managed_toplevel_l2tpipsec.onc

{
  "Certificates": [],
  "NetworkConfigurations": [
    {
      "GUID": "{926b84e4-f2c5-0972-b9bbb8f44c4316f5}",
      "Name": "MyL2TPVPN",
      "Type": "VPN",
      "VPN": {
        "Host": "l2tp.acme.org",
        "IPsec": {
          "AuthenticationType": "Cert",
          "IKEVersion": 1,
          "ClientCertType": "Ref",
          "ClientCertRef": "a cert ref",
          "SaveCredentials": false,
          "ServerCARefs": ["ref1", "ref2"]
        },
        "L2TP": {
          "Recommended": [
            "Username",
            "Password"
          ]
         },
        "Type": "L2TP-IPsec"
      }
    }
  ],
  "Type": "UnencryptedConfiguration"
}