PPTP VPN connection suddenly playing up

[VirtualWolf]

I’ve got an Intel Mac mini running 10.5.2 Server behind an 802.11n AirPort Extreme. It does VPN/AFP/OD/DNS/DHCP, etc. The whole setup has been working flawlessly, but sometime over the last few days the VPN has pretty much shat itself. There haven’t been any software changes whatsoever. I’ve only got port 1723 forwarded from the Extreme to the mini.

Generally what happens when I connect now is either it’ll just come up with an error saying “Could not negotiate a connection with the remote server”, or it [i]will[/i] connect but there’s absolutely no data being transferred through the connection. When that happens I can’t even ping the remote IP of the server (10.0.1.253) or anything.

When it errors out and doesn’t connect at all this is what the logs have:

[quote][code]Apr 17 16:38:00 pppd[1001]: pppd 2.4.2 (Apple version 314) started by root, uid 506
Apr 17 16:38:00 pppd[1001]: PPTP connecting to server ‘xxxxxxxx’ (xxx.xxx.xxx.xxx)…
Apr 17 16:38:01 pppd[1001]: PPTP connection established.
Apr 17 16:38:01 pppd[1001]: Connect: ppp0 <--> socket[34:17]
Apr 17 16:38:31 pppd[1001]: LCP: timeout sending Config-Requests
Apr 17 16:38:31 pppd[1001]: Connection terminated.
Apr 17 16:38:31 pppd[1001]: PPTP disconnecting…
Apr 17 16:38:31 pppd[1001]: PPTP disconnected[/code][/quote]

When the connection occurs it gives this:

[quote][code]Apr 17 16:41:35 pppd[1010]: pppd 2.4.2 (Apple version 314) started by root, uid 506
Apr 17 16:41:35 pppd[1010]: PPTP connecting to server ‘xxxxxxxx’ (xxx.xxx.xxx.xxx)…
Apr 17 16:41:35 pppd[1010]: PPTP connection established.
Apr 17 16:41:35 kernel[0]: pptp_input unexpected, so = 0x38de000, len = 29
Apr 17 16:41:35 pppd[1010]: Connect: ppp0 <--> socket[34:17]
Apr 17 16:41:39 pppd[1010]: MPPE 128-bit stateless compression enabled
Apr 17 16:41:39 pppd[1010]: local IP address 10.0.1.241
Apr 17 16:41:39 pppd[1010]: remote IP address 10.0.1.253
Apr 17 16:41:39 pppd[1010]: primary DNS address 10.0.1.253
Apr 17 16:41:39 pppd[1010]: secondary DNS address 10.0.1.253
Apr 17 16:41:39 mDNSResponder[23]: Note: DNS Server 10.0.1.253 for domain core. registered more than once[/code][/quote]

And now that I’m looking at that I haven’t seen the “pptp_input unexpected” message before. After a few minutes the connection will disconnect and give an error “The connection was terminated because the remote side is not responding”.

I fiddled around a while ago trying to get L2TP to work but never got it going. I can give that another try, and I will grant that I haven’t actually tried restarting the server yet (I’m at work right now and seeing as how I can’t VPN in I can’t remotely restart it!). I [i]have[/i] tried restarting the VPN service last night though, which evidently had no effect.

Any thoughts?

[VirtualWolf]

So, I got home and found out we had a blackout today! So no need to restart the server. 😛

I’m thinking that perhaps that might have broken something though, because I’ve set up L2TP as well, and now both it and PPTP consistently get to the “Authenticating” stage and get no further. The VPN log on the server reports this:

[quote][code]Thu Apr 17 20:55:04 2008 : PPTP incoming call in progress from ‘119.11.4.22’…
Thu Apr 17 20:55:04 2008 : PPTP connection established.
Thu Apr 17 20:55:04 2008 : using link 0
Thu Apr 17 20:55:04 2008 : Using interface ppp0
Thu Apr 17 20:55:04 2008 : Connect: ppp0 <--> socket[34:17]
Thu Apr 17 20:55:04 2008 : sent [LCP ConfReq id=0x1 ]
Thu Apr 17 20:55:04 2008 : rcvd [LCP ConfReq id=0x1 ]
Thu Apr 17 20:55:04 2008 : lcp_reqci: returning CONFACK.
Thu Apr 17 20:55:04 2008 : sent [LCP ConfAck id=0x1 ]
Thu Apr 17 20:55:07 2008 : sent [LCP ConfReq id=0x1 ]
Thu Apr 17 20:55:07 2008 : rcvd [LCP ConfReq id=0x1 ]
Thu Apr 17 20:55:07 2008 : lcp_reqci: returning CONFACK.
Thu Apr 17 20:55:07 2008 : sent [LCP ConfAck id=0x1 ]
Thu Apr 17 20:55:07 2008 : rcvd [LCP ConfAck id=0x1 ]
Thu Apr 17 20:55:07 2008 : sent [LCP EchoReq id=0x0 magic=0x6e42c470]
Thu Apr 17 20:55:07 2008 : sent [CHAP Challenge id=0x2 <53a3cdc556c18fbcf8d52f348e808215>, name = “sprite.core”]
Thu Apr 17 20:55:07 2008 : rcvd [LCP EchoReq id=0x0 magic=0x1b95df8c]
Thu Apr 17 20:55:07 2008 : sent [LCP EchoRep id=0x0 magic=0x6e42c470]
Thu Apr 17 20:55:07 2008 : rcvd [LCP EchoRep id=0x0 magic=0x1b95df8c]
Thu Apr 17 20:55:07 2008 : rcvd [CHAP Response id=0x2 , name = “virtualwolf”]
Thu Apr 17 21:00:39 2008 : sent [CHAP Success id=0x2 “S=61726C6707EC5B0EF707D530EADA03D587EB6F52 M=Access granted”]
Thu Apr 17 21:00:39 2008 : CHAP peer authentication succeeded for virtualwolf
Thu Apr 17 21:00:42 2008 : DSAccessControl plugin: User ‘virtualwolf’ authorized for access
Thu Apr 17 21:00:42 2008 : sent [CCP ConfReq id=0x1 ]
Thu Apr 17 21:00:42 2008 : PPTP hangup
Thu Apr 17 21:00:42 2008 : Connection terminated.
Thu Apr 17 21:00:42 2008 : Connect time 5.7 minutes.
Thu Apr 17 21:00:42 2008 : Sent 0 bytes, received 0 bytes.
Thu Apr 17 21:00:42 2008 : PPTP disconnecting…
Thu Apr 17 21:00:42 2008 : PPTP disconnected[/code][/quote]

[VirtualWolf]

I’ve done more fiddling, I temporarily got things going by running the vpnaddkeyagentuser on the server, and it was working for a day, but it appears to have broken again. I can either connect but no traffic is passed through, or it just won’t connect at all. 🙁

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