I am having problems with SSH and Kleoptra when running L2TP/IPSec.
My setup includes my PC (Windows7/64) running GOG’s Kleopatra connected to…
… an RB2011 (routeros 6.5) which is running L2TP/IPSec Client over a PPPoE to…
… a TPLink 8816 ADSL Modem onto BT supplied-internet to …
… a VPN service provided by iVPN, terminating in Holland, France or Canada depending on how I have it configured.
I am pretty sure the IPSec connection is working correctly; I can see the SPIs reset every 30 minutes or so (as set up). The logging from the IPSec looks sensible, with no errors. IPLocation services give my location as Holland, France or Canada when the VPN is active, or London (where I am) when it is disabled.
All other internet applications seem to work correctly, namely web browsing (80 and 443), mail (25), secure mail (465 I think), iTunes, Spotify, DropBox, iCloud, Bittorrent, the lot. Everything seems to be ok.
However, when I try to GIT “push” to repositoryhosting.com, using SSH, the remote write starts sending, then stalls, then finally fails with “software error” from GIT after about 10 seconds. The same operation works perfectly if I route directly to the BT PPPoE interface instead of the L2TP interface (whilst leaving the L2TP running).
Also, I notice that when VPN routing is enabled for my PC, Kleopatra seems to take 5 minutes to load up instead of 10 seconds.
Does anyone have any idea how to debug this?
I won’t load up the router configuration at the moment, as I was hoping someone could suggest an external SSH test site somewhere on the internet that could help me diagnose the issue, or perhaps there is a VPN test site somewhere?
I suspect that it might be due to packet fragmentation, and something to do with the MSS/MTU/MRU settings, but don’t really know how to debug it.