we are trying to connect to a BM 3.8 server for vpn purposes over an adsl
line via a draytek 2600 router, but the authentication fails. When we
replace the router with an adsl modem the connection is ok. We have enabled
vpn passthrough on the draytek, have opened up ports tcp 50, udp 500, tcp
353, udp 353 udp 2010, udp 4500, tcp 57, tcp 213. Does anyone have any
ideas what to try next?

Mark Corfield
Pangaea Consulting