Cannot connect using openVPN

Cannot connect using openVPN
Links: home · search · speed test · login · more ·

Links: Reply New Topic
Forums » Up and Running » Virtual Private Networking » Cannot connect using openVPN

matrix1984 @ 26th Sep 08:36PM:
Cannot connect using openVPN

I'm located in SE Asia. As of mid July I can no longer connect to Perfect-Privacy servers using openVPN or SSH. This has happened to both my desktop and my laptop. I was travelling through multiple countries and the problem remained on my laptop. My desktop worked prior to me leaving China, but doesn't work anymore upon my return, so that rules out something I installed, or a Windows update. Following is an excerpt from the log file at the point where both my computers hang in the login process:

Sun Sep 27 08:28:39 2009 us=468000 Fragmentation MTU parms [ L:1562 D:1300 EF:61 EB:135 ET:1 EL:0 AF:3/1 ]
Sun Sep 27 08:28:39 2009 us=468000 Local Options String: 'V4,dev-type tun,link-mtu 1562,tun-mtu 1500,proto UDPv4,comp-lzo,mtu-dynamic,keydir 1,cipher AES-256-CBC,auth SHA1,keysize 256,tls-auth,key-method 2,tls-client'
Sun Sep 27 08:28:39 2009 us=468000 Expected Remote Options String: 'V4,dev-type tun,link-mtu 1562,tun-mtu 1500,proto UDPv4,comp-lzo,mtu-dynamic,keydir 0,cipher AES-256-CBC,auth SHA1,keysize 256,tls-auth,key-method 2,tls-server'
Sun Sep 27 08:28:39 2009 us=468000 Local Options hash (VER=V4): 'e05aa1c5'
Sun Sep 27 08:28:39 2009 us=468000 Expected Remote Options hash (VER=V4): '0088baee'
Sun Sep 27 08:28:39 2009 us=468000 Socket Buffers: R=[8192->8192] S=[8192->8192]
Sun Sep 27 08:28:39 2009 us=468000 UDPv4 link local: [undef]
Sun Sep 27 08:28:39 2009 us=468000 UDPv4 link remote: 67.220.68.52:1149
Sun Sep 27 08:28:39 2009 us=718000 read UDPv4: Net dropped connection or reset (WSAENETRESET) (code=10052)
Sun Sep 27 08:28:42 2009 us=46000 read UDPv4: Net dropped connection or reset (WSAENETRESET) (code=10052)
Sun Sep 27 08:28:43 2009 us=312000 read UDPv4: Net dropped connection or reset (WSAENETRESET) (code=10052)
Sun Sep 27 08:28:45 2009 us=703000 read UDPv4: Net dropped connection or reset

I've obviously uninstalled and reinstalled with the most current versions of openVPN, as well as been in contact with their techsupport, but no resolution is in site short of switching to a new VPN. I welcome any advice or opinions from all you experts! Thanks!
reply

vpn12 @ 30th Sep 12:59PM:
Re: Cannot connect using openVPN

Could be a coincidence, but the IP in your logfile is not routed properly. From where I am the traceroute goes in a loop.

Switch server I would. I assume they have more than one.
reply

robo_geek @ 30th Sep 09:58PM:
Re: Cannot connect using openVPN

WSAENETRESET are socket/protocol failures.

Here are some clues:

a) XP SP3 has some weird UDP issues, all done in the name of security.

b) There have been some patches from MSFT for some weird networking issues such that going from SP1 to SP2 broke some things: »support.microsoft.com/kb/897656/

Some malware hoses up the IP stack, so that a stack reset can sometimes help.

Note that since UDP packets are connectionless, an incorrect MTU at any part of the path may cause fragmentation. So wrong MTU will kill your VPN auth process every time.

In the case of microsoft VPN, you can force it to use TCP instead of UDP for AD authentication which sidesteps this sort of problem. support.microsoft.com/kb/244474
reply