VPN running but not responding to clients

Question

VPN running but not responding to clients

I have a MacPro 2008 with MacOs X Server 10.6.5
Have setup the server, and want to use VPN.

Setup LT2P, made a shared secret etc.
FireWall is turned off
VPN is running and vpnd is shown as process

When i try locally to setup a VPN connection, i keep getting LT2P Server not responding
When i do a port scan no port that uses VPN (500, 4500, 1701) are open.

i Use only one ethernet port.
Where to look, log is not shoming anything execpt listining ....

Multiple Systems, Mac OS X (10.6.5), MacOS X Server 10.6.5

Posted on Dec 30, 2010 5:51 AM

Reply

Answer 1

Dec 30, 2010 6:35 AM in response to Patrick Savelberg (Private)

Just to make sure - you don't have your starting and ending IP addresses for VPN overlapping or using the same IP addresses that you DHCP server hands out - do you?

Also, can you post the output of $ sudo serveradmin fullstatus vpn

Reply

Answer 2

Dec 30, 2010 6:53 AM in response to Nachos Libres

No it is not overlapping my DHCP.

Here is the full output :

vpn:servicePortsAreRestricted = "NO"
vpn:readWriteSettingsVersion = 1
vpn:servers:com.apple.ppp.pptp:AuthenticationProtocol = "MSCHAP2"
vpn:servers:com.apple.ppp.pptp:CurrentConnections = 0
vpn:servers:com.apple.ppp.pptp:enabled = no
vpn:servers:com.apple.ppp.pptp:MPPEKeySize = "MPPEKeySize128"
vpn:servers:com.apple.ppp.pptp:Type = "PPP"
vpn:servers:com.apple.ppp.pptp:SubType = "PPTP"
vpn:servers:com.apple.ppp.pptp:AuthenticatorPlugins = "DSAuth"
vpn:servers:com.apple.ppp.l2tp:AuthenticationProtocol = "MSCHAP2"
vpn:servers:com.apple.ppp.l2tp:CurrentConnections = 0
vpn:servers:com.apple.ppp.l2tp:enabled = yes
vpn:servers:com.apple.ppp.l2tp:startedTime = "2010-12-30 15:28:52 +0100"
vpn:servers:com.apple.ppp.l2tp:Type = "PPP"
vpn:servers:com.apple.ppp.l2tp:SubType = "L2TP"
vpn:servers:com.apple.ppp.l2tp:AuthenticatorPlugins = "DSAuth"
vpn:servers:com.apple.ppp.l2tp:pid = 1606
vpn:servicePortsRestrictionInfo = emptyarray
vpn:health = emptydictionary
vpn:logPaths:com.apple.ppp.pptp_ServerLog = "/var/log/ppp/vpnd.log"
vpn:logPaths:com.apple.ppp.pptp_PPPLog = "/var/log/ppp/vpnd.log"
vpn:logPaths:vpnLog = "/var/log/ppp/vpnd.log"
vpn:configured = yes
vpn:state = "RUNNING"
vpn:setStateVersion = 1

It is a standard installation, and i have done it multiple times with other machines.

[edit] checked my other installation and the output is the same.

Reply

Answer 3

Dec 30, 2010 8:48 AM in response to Patrick Savelberg (Private)

The only other thing I can think of is to make sure you have a DNS entry on your DNS server for the server hosting VPN and making sure you have the IP address of the DNS server entered under Settings and Client Information in VPN.

It could also be that those ports are being firewalled but you already said your firewall wasn't running.

Reply

Answer 4

Dec 30, 2010 11:42 PM in response to Patrick Savelberg (Private)

You can't use Network Utility to scan for open UPD ports, you need something like nmap.

Nothing in ppp.log?

Entering login name exactly as it is entered in WGM/account from OD or Local db, use either the long name or the first short name.

No SACL is used for the VPN service (default is SACL is not in place for VPN)?

Reply

Answer 5

Dec 31, 2010 9:55 PM in response to Patrick Savelberg (Private)

Check to make sure the shared secret is entered correctly (on both server and client) -- if it's wrong, you get the same error as if the server just isn't responding at all.

Reply

Answer 6

kjelt

Level 1

5 points

Jan 22, 2011 4:33 PM in response to Patrick Savelberg (Private)

I am having the same problem...vpnd is sitteng there, listening, but does not react to any connection attempts (not even from the same machine)

ppp.log says

Sun Jan 23 01:28:51 2011 : L2TP connecting to server '192.168.0.51' (192.168.0.51)...
Sun Jan 23 01:28:51 2011 : IPSec connection started
Sun Jan 23 01:29:01 2011 : IPSec connection failed

Reply

Answer 7

kjelt

Level 1

5 points

Jan 24, 2011 7:22 AM in response to kjelt

follow-up:

I had an error in the "shared secret" set-up, now its working without problems...so the advice above is true: check the authentication throughly, as errors here show up very much like no connection between client and server was established

cheers, kjelt

(I think, my testing it locally was senseless, that can't work in any case)

Reply

Answer 8

Jan 27, 2011 4:40 AM in response to kjelt

Nope, the pre-sharedkey is correct.

The only thing i can think off, the previous system administrator is setup the network in the range:
192.128.0.x
This is not o private network range that is used private.
Can this be the issue, i have setup dozen of VPN's this way and only this one is not working.

Al already did a clean install again.

Reply

Answer 9

Jan 27, 2011 7:04 AM in response to Patrick Savelberg (Private)

IP routing does not appreciate having the same subnet on both ends of a VPN.

I'd get out of 192.168.0.0/24 and 192.168.1.0/24 subnets given the prevalence of those subnets on home WiFi and coffee shop networks and given the connectivity problems that the use of duplicate IP subnets causes for VPN IP routing, and preferably get your networks entirely out of the 192.168.0.0/16 block, and preferably into a subnet somewhere in the 10.0.0.0/8 or 172.16.0.0/16 blocks.

I'd also suggest adding a VPN-capable firewall.

VPN pass-through with a NAT device is problematic at best. Add to that that various of the Apple Airport and Time Capsule devices have had various forum reports of firmware issues with VPN passthrough with L2TP over the years. And yes, these are among the reasons why I tend to go immediately to a server-grade gateway firewall device.

Reply

Answer 10

Feb 1, 2011 6:39 PM in response to MrHoffman

I have had issues with this from the beginning. Just had the girl friend turn VPN off and then back on to get it to work since I'm out of town. Apple needs to fix this before they post sites like this...

http://www.apple.com/server/macosx/features/networking-vpn.html

You do have to be a network guru to set up Snow Leopard server. Now if I could just get my Airport express to work with the server. Man!

Reply

Answer 11

Feb 4, 2011 8:15 AM in response to koa_noise

Welcome to the forums.

Consider purchasing equipment suited for the task.

Airport Extreme (AX) and Time Capsule (TC) are not what I would consider server-grade gateway devices; they're fairly feature-weak when server-oriented networking is involved.

These Apple devices are NAT-based firewalls, and can be appropriate for home use.

If you are planning to perform inbound connections typical of servers, these devices lack port-mapping flexibility, VPN end-point capabilities, multiple public IP addresses, and DMZ features.

And FWIW, if you're going to operate with VPN pass-through and NAT using an AX or TC, there is an [Apple tech note (HT3944)|http://support.apple.com/kb/HT3944] around shutting off MobileMe on the AX or TC to get the L2TP VPN pass-through connections to function.

Reply

Answer 12

Jerry Z.

Level 1

120 points

May 21, 2011 6:30 PM in response to MrHoffman

Brilliant! This is the document that I have been looking for and which clears up hours of frustration for me.

Thanks!

Reply

Answer 13

Aug 3, 2012 5:07 PM in response to koa_noise

I'm happy to say that the VPN on my Snow Leopard server has been flawless over the last few months. Maybe the fix was through my Airport Extreme or the server either way this is awesome!

Reply

Answer 14

einord

Level 1

10 points

May 23, 2013 12:27 AM in response to MrHoffman

Fantastic! Thanks!

Reply