[Bug 1118705] [NEW] openvpn connection stalls

[Robert Gierzinger]

Public bug reported:

Distribution Used:    Ubuntu 12.04.2 LTS  with all latest updates
Package: openvpn 2.2.1-8ubuntu1
Kernel: 3.2.0-36-generic #57 - 64bit

At first I dug into the docs of openvpn and tried various configurations with different parameters for options "fragment", "tun-mtu", "mssfix". Connections via openvpn seemed to stall after a certain amount of data transmitted or time. I discovered the issue a few seconds after establishing a remote desktop connection session to a windows computer.
I found similar problems here: https://forums.openvpn.net/topic9401.html
However, even filetransfers via ssh to any of our linux servers behind the firewall (which is also this openvpn end point) stalled after 5-15 MB. As mentioned before even with different mtu sizes/fragments and from different dial-in connections.

The server is an IBM x3550 m4 with standard components located in a
datacenter. eth0 is connected to the uplink, eth1+eth2 bundled as bond0
to a switch where the DMZ is. This server also has a openvpn connection
to our corporate headquarters: even without the bonding interface
involved (a bug there was my first guess) the connection stalled.
However, if I connected to the endpoint of the corporate headquarters
the problem did not occur - here we use up-to-date Ubuntu 12.04 but with
32 bit.

Openvpn option mtu-test just resulted in a strange log-message "NOTE:
failed to empirically measure MTU (requires OpenVPN 1.5 or higher at
other end of connection)". Logfiles also did not give any information.

Solution: 
adding the snapshot repository from https://community.openvpn.net/openvpn/wiki/OpenvpnSoftwareRepos  and installing openvpn 2.3.0 resolved the issue.

** Affects: openvpn (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/1118705

Title:
  openvpn connection stalls

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