When you do thisover ADSL is there some MTU Overhead for the VPN also.
It is failing even though we can ping end points.
I.e Outlook fails even though telner 25 works so seems to be some packet size issue over the VPN.
Had the same problem for regular traffic without a VPN but adjusted various MTU / PMTU sizes and all seemed OK.
Is there an equivalent for VPN MTU ?G