sudden and costly RAS problems

[Coban]

I have 3 VPN clients that connect to my server daily. 2 of the clients are
running NT 4.0 and the 3rd client is running Windows 2000.

1 of the NT clients is connecting without issue.

The other NT client and the Windows 2000 client which are at the same
location cannot connect.
Internet access has been verified so that is not an issue... I can ping
what and whoever and I can load internet pages as well.

The NT client is getting a 678 error, stating that there is no answer
The 2000 client gets a 781 encryption error telling me that no vaild
certificate was found.
I do not see any errors logged on my server telling me about failed
validation attempts.
Both clients connect without a problem using THE EXACT SAME PROTOCOLS over a
modem dial-up connection.

Why oh why can't I connect these 2 clients over the internet? They've been
doing this daily for over a year and no settings have been changed.

TIA, Ari

 

[Priya Raghavan [MSFT]]

Hi,
From the Win 2000 client, are you trying to establish L2TP connection? if
so, you should have valid certificates in the machine store and its root in
the trusted root CA of the server.

Thanks,
Priya.