There on remote site we have 2 gateways
GW1: One to the Internet through an ADSL connection, it's a FreeBSD Server
GW2: Another to our headquarter through a dedicate line..NBM is here on the
headquarter, it's a Netware Server

On NBM, on the logger screen, it shows messages: AUTHCHK.NLM: IP Address
A.B.C.D attempted to Spoof X.Y.W.Z
Where, A.B.C.D is the workstations IP addresses and X.Y.W.Z is the ADSL
connection on the remote site.

I think some made some mistake on network, and now i have to fix it :(

Workstations are set to use GW2 as default gateway.
Tracert to NBM runs fine through GW2.

Any Ideas?

Thankyou in advance!