IKEV2

NEVPNProtocolIPSec *p = (NEVPNProtocolIPSec*)_vpnManager.protocol;
            if (!p) {
                p = [[NEVPNProtocolIPSec alloc] init];
            }

            p.username = _ID;
            p.serverAddress = _server;
            //p.serverCertificateIssuerCommonName = @"COMODO RSA Domain Validation Secure Server CA";
            p.remoteIdentifier = remoteID;//@"hide.me";
            p.passwordReference = [self searchKeychainCopyMatching:VPN_PwdIdentifier];
            p.authenticationMethod = NEVPNIKEAuthenticationMethodSharedSecret;//NEVPNIKEAuthenticationMethodSharedSecret;
            p.sharedSecretReference = [self searchKeychainCopyMatching:VPN_PrivateKeyIdentifier];
            p.useExtendedAuthentication = YES;
            p.disconnectOnSleep = NO;

            _vpnManager.protocol = p;
            _vpnManager.onDemandEnabled=YES;
            _vpnManager.localizedDescription = _vpnTitle?_vpnTitle:@"Ipsec Test"; //设置VPN的名字 可以自定义

            // 保存设置
            [_vpnManager saveToPreferencesWithCompletionHandler:^(NSError *error) {
                if(error) {
                    completeHandle(NO,[NSString stringWithFormat:@"Save config failed [%@]", error.localizedDescription]);
                }
                else {
                    completeHandle(YES,@"Save config success");
                }
            }];