Due to security features of Windows NT, 2000 and XP it may be necessary to use NTFEN1 instead of the preferred NTFEN2 to allow Ethernet communication with the 6K.
Windows NT/2000/XP will only allow users with Administrator privileges to statically map(ARP -S)the Ethernet/MAC address to the IP address. This requires that all users have Administrator privileges on the NT/2000/XP computer which produces security issues for Network Administrators.
If the 6K is NOT located on a network, i.e. using a direct connection Ethernet cable, it may be preferrable to use NTFEN1 setting.
If the 6K is to be located on a network, use a Win9X/ME workstation instead with the 6K set to NTFEN2 and statically map the Ethernet address.
If it is necessary to use a WinNT/2000/XP workstation on a network, use a second network interface card in the workstation to isolate the 6K from the rest of the network and use the NTFEN1 setting.