I have a VPN (PPTP) connection set up in Mac OS X that has previously worked flawlessly. Now I'm using a new Internet connection and now it only works some times (without modifying anything); mostly it doesn't. The internet connection that is giving me trouble is a cable modem connected to a Linksys WRT 45G to which I'm connecting wirelessly.
Here's what it looks like in /var/log/ppp.log when it does:
Sun Jan 3 14:55:17 2010 : PPTP connecting to server 'example.com' (XXX.XXX.XXX.XXX)...
Sun Jan 3 14:55:17 2010 : PPTP connection established.
Sun Jan 3 14:55:17 2010 : Using interface ppp0
Sun Jan 3 14:55:17 2010 : Connect: ppp0 <--> socket[34:17]
Sun Jan 3 14:55:21 2010 : MPPE 128-bit stateless compression enabled
Sun Jan 3 14:55:24 2010 : local IP address XXX.XXX.XXX.XXX
Sun Jan 3 14:55:24 2010 : remote IP address XXX.XXX.XXX.XXX
Sun Jan 3 14:55:24 2010 : primary DNS address XXX.XXX.XXX.XXX
Sun Jan 3 14:55:24 2010 : secondary DNS address XXX.XXX.XXX.XXX
Sun Jan 3 14:55:57 2010 : Hangup (SIGHUP)
Sun Jan 3 14:55:57 2010 : MPPE disabled
Sun Jan 3 14:55:57 2010 : Connection terminated.
Sun Jan 3 14:55:57 2010 : Connect time 0.7 minutes.
Sun Jan 3 14:55:57 2010 : Sent 442 bytes, received 268 bytes.
Sun Jan 3 14:55:57 2010 : PPTP disconnecting...
Sun Jan 3 14:55:57 2010 : PPTP disconnected
And when it doesn't:
Mon Jan 4 00:49:25 2010 : PPTP connecting to server 'example.com' (XXX.XXX.XXX.XXX)...
Mon Jan 4 00:49:27 2010 : PPTP connection established.
Mon Jan 4 00:49:27 2010 : Using interface ppp0
Mon Jan 4 00:49:27 2010 : Connect: ppp0 <--> socket[34:17]
Mon Jan 4 00:49:47 2010 : PPTP hangup
Mon Jan 4 00:49:47 2010 : Connection terminated.
Mon Jan 4 00:49:47 2010 : PPTP disconnecting...
Mon Jan 4 00:49:47 2010 : PPTP disconnected
It may have something to do with the ISP since I've heard they do some NATing that sometimes causes problems but I don't know exactly where the problem lies.
After further testing I got an error 619 from Windows Vista and this from the ppp.log:
[2184] 01-04 13:28:04:995: PPPEMSG_Start recvd, d=, hPort=4,callback=0,mask=8821288,IfType=-1
[3872] 01-04 13:28:04:995: Line up event occurred on port 4
[3872] 01-04 13:28:04:995: Local identification = MSRAS-0-FOO1-67
[3872] 01-04 13:28:04:995: PortName: VPN1-1
[3872] 01-04 13:28:04:995: Starting PPP on link with IfType=0xffffffff,IPIf=0xffffffff,IPv6If=0xffffffff,IPXIf=0xffffffff
[3872] 01-04 13:28:04:995: RasGetBuffer returned 89cd020 for SendBuf
[3872] 01-04 13:28:04:995: FsmInit called for protocol = c021, port = 4
[3872] 01-04 13:28:04:995: ConfigInfo = 8821288
[3872] 01-04 13:28:04:995: APs available = a
[3872] 01-04 13:28:04:995: FsmReset called for protocol = c021, port = 4
[3872] 01-04 13:28:04:995: Inserting port in bucket # 4
[3872] 01-04 13:28:04:995: Inserting bundle in bucket # 6
[3872] 01-04 13:28:04:995: FsmOpen event received for protocol c021 on port 4
[3872] 01-04 13:28:04:995: FsmThisLayerStarted called for protocol = c021, port = 4
[3872] 01-04 13:28:04:995: FsmUp event received for protocol c021 on port 4
[3872] 01-04 13:28:04:995: <PPP packet sent at 01/04/2010 19:28:04:995
[3872] 01-04 13:28:04:995: <Protocol = LCP, Type = Configure-Req, Length = 0x17, Id = 0x0, Port = 4
[3872] 13:28:04:995: <C0 21 01 00 00 15 01 04 05 78 05 06 48 AC 5A 45 |.!.......x..H.ZE|
[3872] 13:28:04:995: <07 02 08 02 0D 03 06 00 00 00 00 00 00 00 00 00 |................|
[3872] 01-04 13:28:04:995:
[3872] 01-04 13:28:04:995: InsertInTimerQ called portid=10,Id=0,Protocol=c021,EventType=0,fAuth=0
[3872] 01-04 13:28:04:995: InsertInTimerQ called portid=10,Id=0,Protocol=0,EventType=3,fAuth=0
[3872] 01-04 13:28:07:023: Recv timeout event received for portid=10,Id=0,Protocol=c021,fAuth=0
[3872] 01-04 13:28:07:101: NotifyCaller(hPort=4, dwMsgId=9)
[3872] 01-04 13:28:07:116: <PPP packet sent at 01/04/2010 19:28:07:1
