Is it possible to access VPN clients direct from server?

[virtualitas]

Dear all,

maybe a noob question - maybe I missed something during configuration.
But is it possible to access VPN clients direct from the VPN Server?

Thank you

[solo]

Yes, of course. Before you ask "how", it depends on your server's configuration - pity you didn't bother to describe it.

[virtualitas]

Hi,

it's just a VPN Dial in without any switches. The VPN Server is standalone on a small VPS and used to bypass a restrictive firewall.
Target is to provide some webservices via the VPS and set up a reverse proxy up there. I know, that it would be very performant, but it's just a school project.
I am using the in Softether included SecureNAT at the moment.

The config file:
# Software Configuration File
# ---------------------------
#
# You may edit this file when the VPN Server / Client / Bridge program is not running.
#
# In prior to edit this file manually by your text editor,
# shutdown the VPN Server / Client / Bridge background service.
# Otherwise, all changes will be lost.
#
declare root
{
uint ConfigRevision 14
bool IPsecMessageDisplayed true
string Region US
bool VgsMessageDisplayed false

declare DDnsClient
{
bool Disabled false
byte Key XXXXXXXXXXXXXX
string LocalHostname XXXXXXXXXXX
string ProxyHostName $
uint ProxyPort 0
uint ProxyType 0
string ProxyUsername $
}
declare IPsec
{
bool EtherIP_IPsec false
string IPsec_Secret vpn
string L2TP_DefaultHub DEFAULT
bool L2TP_IPsec false
bool L2TP_Raw false

declare EtherIP_IDSettingsList
{
}
}
declare ListenerList
{
declare Listener0
{
bool DisableDos false
bool Enabled true
uint Port 443
}
declare Listener1
{
bool DisableDos false
bool Enabled true
uint Port 992
}
declare Listener2
{
bool DisableDos false
bool Enabled true
uint Port 1194
}
declare Listener3
{
bool DisableDos false
bool Enabled true
uint Port 5555
}
}
declare LocalBridgeList
{
bool DoNotDisableOffloading false

declare LocalBridge0
{
string DeviceName ens3
string HubName DEFAULT
bool LimitBroadcast false
bool MonitorMode false
bool NoPromiscuousMode false
bool TapMode false
}
}
declare ServerConfiguration
{
bool AcceptOnlyTls true
uint64 AutoDeleteCheckDiskFreeSpaceMin 104857600
uint AutoDeleteCheckIntervalSecs 300
uint AutoSaveConfigSpan 300
bool BackupConfigOnlyWhenModified true
string CipherName AES128-SHA
uint CurrentBuild 9799
bool DisableCoreDumpOnUnix false
bool DisableDeadLockCheck false
bool DisableDosProction false
bool DisableGetHostNameWhenAcceptTcp false
bool DisableIntelAesAcceleration false
bool DisableIPsecAggressiveMode false
bool DisableIPv6Listener false
bool DisableJsonRpcWebApi false
bool DisableNatTraversal false
bool DisableOpenVPNServer false
bool DisableSessionReconnect false
bool DisableSSTPServer false
bool DontBackupConfig false
bool EnableVpnAzure false
bool EnableVpnOverDns false
bool EnableVpnOverIcmp false
byte HashedPassword XXXXXXXXXXXXXXX
string KeepConnectHost keepalive.softether.org
uint KeepConnectInterval 50
uint KeepConnectPort 80
uint KeepConnectProtocol 1
uint64 LoggerMaxLogSize 1073741823
uint MaxConcurrentDnsClientThreads 512
uint MaxConnectionsPerIP 256
uint MaxUnestablishedConnections 1000
bool NoHighPriorityProcess false
bool NoLinuxArpFilter false
bool NoSendSignature false
string OpenVPNDefaultClientOption dev-type$20tun,link-mtu$201500,tun-mtu$201500,cipher$20AES-128-CBC,auth$20SHA1,keysize$20128,key-method$202,tls-client
string OpenVPN_UdpPortList 1194
bool SaveDebugLog false
byte ServerCert XXXXXXXXXXXXXXX
byte ServerKey XXXXXXXXXXXXXXX
uint ServerLogSwitchType 4
uint ServerType 0
bool StrictSyslogDatetimeFormat false
bool Tls_Disable1_0 false
bool Tls_Disable1_1 false
bool Tls_Disable1_2 false
bool Tls_Disable1_3 false
bool UseKeepConnect true
bool UseWebTimePage false
bool UseWebUI false

declare GlobalParams
{
uint FIFO_BUDGET 10240000
uint HUB_ARP_SEND_INTERVAL 5000
uint IP_TABLE_EXPIRE_TIME 60000
uint IP_TABLE_EXPIRE_TIME_DHCP 300000
uint MAC_TABLE_EXPIRE_TIME 600000
uint MAX_BUFFERING_PACKET_SIZE 2560000
uint MAX_HUB_LINKS 1024
uint MAX_IP_TABLES 65536
uint MAX_MAC_TABLES 65536
uint MAX_SEND_SOCKET_QUEUE_NUM 128
uint MAX_SEND_SOCKET_QUEUE_SIZE 2560000
uint MAX_STORED_QUEUE_NUM 1024
uint MEM_FIFO_REALLOC_MEM_SIZE 655360
uint MIN_SEND_SOCKET_QUEUE_SIZE 320000
uint QUEUE_BUDGET 2048
uint SELECT_TIME 256
uint SELECT_TIME_FOR_NAT 30
uint STORM_CHECK_SPAN 500
uint STORM_DISCARD_VALUE_END 1024
uint STORM_DISCARD_VALUE_START 3
}
declare ServerTraffic
{
declare RecvTraffic
{
uint64 BroadcastBytes 1003251561
uint64 BroadcastCount 4627121
uint64 UnicastBytes 323455617
uint64 UnicastCount 989544
}
declare SendTraffic
{
uint64 BroadcastBytes 1120842941
uint64 BroadcastCount 5169734
uint64 UnicastBytes 75815531
uint64 UnicastCount 132136
}
}
declare SyslogSettings
{
string HostName $
uint Port 0
uint SaveType 0
}
}
declare VirtualHUB
{
declare DEFAULT
{
uint64 CreatedTime 1714001124739
byte HashedPassword XXXXXXXXXXXXXXX
uint64 LastCommTime 1714014974272
uint64 LastLoginTime 1714012975543
uint NumLogin 3
bool Online true
bool RadiusConvertAllMsChapv2AuthRequestToEap false
string RadiusRealm $
uint RadiusRetryInterval 0
uint RadiusServerPort 1812
string RadiusSuffixFilter $
bool RadiusUsePeapInsteadOfEap false
byte SecurePassword XXXXXXXXXXXXXXX
uint Type 0

declare AccessList
{
}
declare AdminOption
{
uint allow_hub_admin_change_option 0
uint deny_bridge 0
uint deny_change_user_password 0
uint deny_empty_password 0
uint deny_hub_admin_change_ext_option 0
uint deny_qos 0
uint deny_routing 0
uint max_accesslists 0
uint max_bitrates_download 0
uint max_bitrates_upload 0
uint max_groups 0
uint max_multilogins_per_user 0
uint max_sessions 0
uint max_sessions_bridge 0
uint max_sessions_client 0
uint max_sessions_client_bridge_apply 0
uint max_users 0
uint no_access_list_include_file 0
uint no_cascade 0
uint no_change_access_control_list 0
uint no_change_access_list 0
uint no_change_admin_password 0
uint no_change_cert_list 0
uint no_change_crl_list 0
uint no_change_groups 0
uint no_change_log_config 0
uint no_change_log_switch_type 0
uint no_change_msg 0
uint no_change_users 0
uint no_delay_jitter_packet_loss 0
uint no_delete_iptable 0
uint no_delete_mactable 0
uint no_disconnect_session 0
uint no_enum_session 0
uint no_offline 0
uint no_online 0
uint no_query_session 0
uint no_read_log_file 0
uint no_securenat 0
uint no_securenat_enabledhcp 0
uint no_securenat_enablenat 0
}
declare CascadeList
{
}
declare LogSetting
{
uint PacketLogSwitchType 4
uint PACKET_LOG_ARP 0
uint PACKET_LOG_DHCP 1
uint PACKET_LOG_ETHERNET 0
uint PACKET_LOG_ICMP 0
uint PACKET_LOG_IP 0
uint PACKET_LOG_TCP 0
uint PACKET_LOG_TCP_CONN 1
uint PACKET_LOG_UDP 0
bool SavePacketLog true
bool SaveSecurityLog true
uint SecurityLogSwitchType 4
}
declare Message
{
}
declare Option
{
uint AccessListIncludeFileCacheLifetime 30
uint AdjustTcpMssValue 0
bool ApplyIPv4AccessListOnArpPacket false
bool AssignVLanIdByRadiusAttribute false
bool BroadcastLimiterStrictMode false
uint BroadcastStormDetectionThreshold 0
uint ClientMinimumRequiredBuild 0
bool DenyAllRadiusLoginWithNoVlanAssign false
uint DetectDormantSessionInterval 0
bool DisableAdjustTcpMss false
bool DisableCheckMacOnLocalBridge false
bool DisableCorrectIpOffloadChecksum false
bool DisableHttpParsing false
bool DisableIPParsing false
bool DisableIpRawModeSecureNAT false
bool DisableKernelModeSecureNAT false
bool DisableUdpAcceleration false
bool DisableUdpFilterForLocalBridgeNic false
bool DisableUserModeSecureNAT false
bool DoNotSaveHeavySecurityLogs false
bool DropArpInPrivacyFilterMode true
bool DropBroadcastsInPrivacyFilterMode true
bool FilterBPDU false
bool FilterIPv4 false
bool FilterIPv6 false
bool FilterNonIP false
bool FilterOSPF false
bool FilterPPPoE false
uint FloodingSendQueueBufferQuota 33554432
bool ManageOnlyLocalUnicastIPv6 true
bool ManageOnlyPrivateIP true
uint MaxLoggedPacketsPerMinute 0
uint MaxSession 0
bool NoArpPolling false
bool NoDhcpPacketLogOutsideHub true
bool NoEnum false
bool NoIpTable false
bool NoIPv4PacketLog false
bool NoIPv6AddrPolling false
bool NoIPv6DefaultRouterInRAWhenIPv6 true
bool NoIPv6PacketLog false
bool NoLookBPDUBridgeId false
bool NoMacAddressLog true
bool NoManageVlanId false
bool NoPhysicalIPOnPacketLog false
bool NoSpinLockForPacketDelay false
bool RemoveDefGwOnDhcpForLocalhost true
uint RequiredClientId 0
uint SecureNAT_MaxDnsSessionsPerIp 0
uint SecureNAT_MaxIcmpSessionsPerIp 0
uint SecureNAT_MaxTcpSessionsPerIp 0
uint SecureNAT_MaxTcpSynSentPerIp 0
uint SecureNAT_MaxUdpSessionsPerIp 0
bool SecureNAT_RandomizeAssignIp false
bool SuppressClientUpdateNotification false
bool UseHubNameAsDhcpUserClassOption false
bool UseHubNameAsRadiusNasId false
string VlanTypeId 0x8100
bool YieldAfterStorePacket false
}
declare SecureNAT
{
bool Disabled false
bool SaveLog true

declare VirtualDhcpServer
{
string DhcpDnsServerAddress 192.168.30.1
string DhcpDnsServerAddress2 0.0.0.0
string DhcpDomainName $
bool DhcpEnabled true
uint DhcpExpireTimeSpan 7200
string DhcpGatewayAddress 192.168.30.1
string DhcpLeaseIPEnd 192.168.30.200
string DhcpLeaseIPStart 192.168.30.10
string DhcpPushRoutes $
string DhcpSubnetMask 255.255.255.0
}
declare VirtualHost
{
string VirtualHostIp 192.168.30.1
string VirtualHostIpSubnetMask 255.255.255.0
string VirtualHostMacAddress 5E-11-2B-F2-D1-06
}
declare VirtualRouter
{
bool NatEnabled true
uint NatMtu 1500
uint NatTcpTimeout 1800
uint NatUdpTimeout 60
}
}
declare SecurityAccountDatabase
{
declare CertList
{
}
declare CrlList
{
}
declare GroupList
{
}
declare IPAccessControlList
{
}
declare UserList
{
declare XXXXXXXXXXXXXX
{
byte AuthNtLmSecureHash XXXXXXXXXXXXXXX
byte AuthPassword XXXXXXXXXXXXXXX
uint AuthType 1
uint64 CreatedTime 1714001391632
uint64 ExpireTime 0
uint64 LastLoginTime 1714012975543
string Note $
uint NumLogin 3
string RealName $
uint64 UpdatedTime 1714001391632

declare Traffic
{
declare RecvTraffic
{
uint64 BroadcastBytes 117564245
uint64 BroadcastCount 542453
uint64 UnicastBytes 64906813
uint64 UnicastCount 95237
}
declare SendTraffic
{
uint64 BroadcastBytes 39431
uint64 BroadcastCount 224
uint64 UnicastBytes 10705414
uint64 UnicastCount 32109
}
}
}
}
}
declare Traffic
{
declare RecvTraffic
{
uint64 BroadcastBytes 1003251561
uint64 BroadcastCount 4627121
uint64 UnicastBytes 323455617
uint64 UnicastCount 989544
}
declare SendTraffic
{
uint64 BroadcastBytes 1120842941
uint64 BroadcastCount 5169734
uint64 UnicastBytes 75815531
uint64 UnicastCount 132136
}
}
}
}
declare VirtualLayer3SwitchList
{
}
}

[solo]

On the VPS install also SE client, set its vNIC to static 192.168.30.2 w/o default gateway and finally connect it to "localhost". Before you start pinging VPN clients on 192.168.30.x ensure their firewalls allow it.