Darn, I've done it all, still doesn't connect! Windows 7 Professional, Lion Server 10.7.5 (all latest, including 10.7.5 supplemental). Mac clients connect just great! FYI the Lion server is behind 2 firewalls, so the Internet one forwards to the internal one, that forwards to the DMZ. VNC works, Mac clients work, but not Windows client.
Here's what I did:
1. Change CurrentControlSet\Control\Lsa\LmCompatibilityLevel = 1 (also with local security policy administrator)
2. Change AssumeUDPEncapsulationContextOnSendRule = 2
3. Forward firewall ports 50-51 UDP (these were not listed on other sites as L2TP or PPTP ports)
4. Reboot
5. Create VPN settings as indicated above for L2TP - still error 789. I also tried PPTP, which should be much simpler, still no connection.
What am I missing? I don't know.
Here's the Windows log tail from the error reporting, I found 2 sections that may be relevant, but they don't tell me much - DisconnectReason = 2, maybe that's error 719?:
[9708] 10-11 14:13:02:116: PortOpen: VPN0-1
[9708] 10-11 14:13:02:117: Opening line in monitor mode
[9708] 10-11 14:13:02:117: PortOpen: successfully opened VPN0-1
[9708] 10-11 14:13:02:118:
[9168] 10-11 14:13:04:437: DeviceConnect: DevSpecificInfo of 96 bytes available. Allocating new memory...
[9168] 10-11 14:13:04:437: DeviceConnect: calling lineMakeCall with size 96 and offset 193
[9168] 10-11 14:13:04:437: DeviceConnect: calling lineMakeCall for VPN0-1, address=[--deleted--]
[9168] 10-11 14:13:04:438: DeviceConnect: Changing state for VPN0-1 from 1 -> 4
[8492] 10-11 14:13:04:438: RasTapicallback: msg=12 , param1=65601l , param2=0l
[8492] 10-11 14:13:04:438: LINE_REPLY. param1=0x10041
[8492] 10-11 14:13:04:438: RasTapicallback: msg=2 , param1=512l , param2=0l
[8492] 10-11 14:13:04:438: RasTapicallback: linecallstate=0x200
[8492] 10-11 14:13:25:449: RasTapicallback: msg=2 , param1=16384l , param2=2147952451l
[8492] 10-11 14:13:25:449: RasTapicallback: linecallstate=0x4000
[8492] 10-11 14:13:25:449: RasTapiCallback: LINECALLSTATE_DISCONNECTED for port VPN0-1. AsyncErr = -2147014845, param2=0x80072743
[7724] 10-11 14:13:25:449: DeviceWork: VPN0-1. State = 4
[8492] 10-11 14:13:25:449: RasTapicallback: msg=2 , param1=1l , param2=0l
[8492] 10-11 14:13:25:449: RasTapicallback: linecallstate=0x1
[9708] 10-11 14:13:25:452: PortDisconnect: VPN0-1
[9708] 10-11 14:13:25:452: InitiatePortDisconnection: VPN0-1
[9708] 10-11 14:13:25:452: InitiatePortDisconnection: Changing state for VPN0-1 from 4 -> 5, id=0x10275
[9708] 10-11 14:13:25:452:
[9708] 10-11 14:13:25:452:
[8492] 10-11 14:13:25:452: RasTapicallback: msg=12 , param1=66165l , param2=0l
[8492] 10-11 14:13:25:452: LINE_REPLY. param1=0x10275
[8492] 10-11 14:13:25:452: RasTapiCallback: lineDropped. port VPN0-1, id=0xffffffff
[8492] 10-11 14:13:25:452: RasTapiCallback: Idle Received for port VPN0-1
[8492] 10-11 14:13:25:452: RasTapiCallback: changing state of VPN0-1. 5 -> 1
[8492] 10-11 14:13:25:452: RasTapiCallback: lineDeallocateCall for VPN0-1,hcall = 0x1001e
[7724] 10-11 14:13:25:453: PortTestSignalState: DeviceState = 0
[9708] 10-11 14:13:25:453: PortClose: VPN0-1
[9708] 10-11 14:13:25:453: No more ports opened for dialout on this line
[9708] 10-11 14:13:25:453: Closing line
[9708] 10-11 14:13:25:454: PortClose: Changing state for VPN0-1 from 1 -> 0
[9708] 10-11 14:13:25:454:
[4828] 10-11 15:00:32:034: PortOpen: VPN3-1
[4828] 10-11 15:00:32:034: Opening line in monitor mode
[4828] 10-11 15:00:32:034: PortOpen: successfully opened VPN3-1
[4828] 10-11 15:00:32:034:
[7232] 10-11 15:00:32:159: DeviceConnect: DevSpecificInfo of 16 bytes available. Allocating new memory...
[7232] 10-11 15:00:32:159: DeviceConnect: calling lineMakeCall with size 16 and offset 193
[7232] 10-11 15:00:32:159: DeviceConnect: calling lineMakeCall for VPN3-1, address=[--deleted--]
[7232] 10-11 15:00:32:159: DeviceConnect: Changing state for VPN3-1 from 1 -> 4
[8640] 10-11 15:00:32:174: RasTapicallback: msg=12 , param1=65785l , param2=0l
[8640] 10-11 15:00:32:174: LINE_REPLY. param1=0x100f9
[8640] 10-11 15:00:32:174: RasTapicallback: msg=2 , param1=512l , param2=0l
[8640] 10-11 15:00:32:174: RasTapicallback: linecallstate=0x200
[8640] 10-11 15:00:34:109: RasTapicallback: msg=2 , param1=256l , param2=0l
[8640] 10-11 15:00:34:109: RasTapicallback: linecallstate=0x100
[8640] 10-11 15:00:34:109: DwGetConnectInfo
[8640] 10-11 15:00:34:109: DwGetIDInformation
[8640] 10-11 15:00:34:109: DwGetIDInformation. 0
[8640] 10-11 15:00:34:109: SizeRequired for CallID=0
[8640] 10-11 15:00:34:109: CallIDSize=ConnectResponseSize=0
[8640] 10-11 15:00:34:109: DwGetConnectInfo. 0x0
[8640] 10-11 15:00:34:109: RasTapiCallback: DwGetConnectInforeturned 0x0
[8640] 10-11 15:00:34:109: RasTapiCallback: Connected on VPN3-1
[8640] 10-11 15:00:34:109: RasTapiCallback: Outgoing call
[1336] 10-11 15:00:34:109: DeviceWork: VPN3-1. State = 4
[1336] 10-11 15:00:34:109: DeviceWork: Changing state for VPN3-1 from 4 -> 3
[4828] 10-11 15:00:34:124: PortConnect: VPN3-1
[4828] 10-11 15:00:34:124:
[8640] 10-11 15:01:04:320: RasTapicallback: msg=2 , param1=16384l , param2=0l
[8640] 10-11 15:01:04:320: RasTapicallback: linecallstate=0x4000
[8640] 10-11 15:01:04:320: RasTapiCallback: lineGetCallStatus for VPN3-1 returned 0x4000
[8640] 10-11 15:01:04:320: RasTapiCallback: DisconnectReason mapped to 2
[8640] 10-11 15:01:04:320: RasTapiCallback: LINECALLSTATE - initiating Port Disconnect
[8640] 10-11 15:01:04:320: InitiatePortDisconnection: VPN3-1
[8640] 10-11 15:01:04:320: InitiatePortDisconnection: Changing state for VPN3-1 from 3 -> 5, id=0x102a5
[8640] 10-11 15:01:04:320:
[8640] 10-11 15:01:04:320: RasTapicallback: msg=2 , param1=1l , param2=0l
[8640] 10-11 15:01:04:320: RasTapicallback: linecallstate=0x1
[8640] 10-11 15:01:04:320: RasTapicallback: msg=12 , param1=66213l , param2=0l
[8640] 10-11 15:01:04:320: LINE_REPLY. param1=0x102a5
[8640] 10-11 15:01:04:320: RasTapiCallback: lineDropped. port VPN3-1, id=0xffffffff
[8640] 10-11 15:01:04:320: RasTapiCallback: Idle Received for port VPN3-1
[8640] 10-11 15:01:04:320: RasTapiCallback: changing state of VPN3-1. 5 -> 1
[8640] 10-11 15:01:04:320: RasTapiCallback: lineDeallocateCall for VPN3-1,hcall = 0x100d7
[1336] 10-11 15:01:04:320: PortTestSignalState: DisconnectReason = 2
[1336] 10-11 15:01:04:320: PortDisconnect: VPN3-1
[1336] 10-11 15:01:04:320: