L2TP VPN on Tiger Server no workie... SOMETIMES

[Noam Birnbaum]

Hey folks,

Here's an issue I've seen A LOT -- probably on half of the Tiger  
Servers we've set up: PPTP works fine, L2TP doesn't even allow  
connections to initiate.

It's not a firewall or router issue; I've duplicated it on the local  
networks, with the server firewall off.  The closest I've got to the  
problem is to determine that server port 1701 (L2TP) is simply not  
accepting connections; port 1723 (PPTP) has no such issue.  See the  
following Terminal transcript, from a workstation on the LAN, no  
firewalling enabled:

workstation:~ noam$ telnet 10.0.5.3 1701
Trying 10.0.5.3...
telnet: connect to address 10.0.5.3: Connection refused
telnet: Unable to connect to remote host
workstation:~ noam$ telnet 10.0.5.3 1723
Trying 10.0.5.3...
Connected to medicalserver.medicaloffice.com.
Escape character is '^]'.

We've duplicated this exact situation on networks using all kinds of  
routers and switches.  It doesn't seem specific to any model, and as  
I've said it only happens on HALF the servers, all using the same  
configuration methodology.

The vpnd.log is annoyingly empty of clues:

#Start-Date: 2007-12-18 09:58:05 PST
#Fields: date time s-comment
2007-12-18 09:58:05 PST	Loading plugin /System/Library/Extensions/ 
L2TP.ppp
2007-12-18 09:58:05 PST	Listening for connections...
#Start-Date: 2007-12-18 09:58:05 PST
#Fields: date time s-comment
2007-12-18 09:58:05 PST	Loading plugin /System/Library/Extensions/ 
PPTP.ppp
2007-12-18 09:58:05 PST	Listening for connections...

I don't know if this same issue occurs on Leopard Server.

Yurk!  Any suggestions?

Thanks,
noam

Noam Birnbaum
http://maccentricsolutions.com/
877.luv.macs x89

 Apple Certified Technical Coordinator
 Apple Certified Help Desk Specialist