Just an FYI, I seem to have fixed our problem. I have added restrict 0.0.0.0 mask 0.0.0.0 nopeer nomodify notrust notrap Which probably should have been there all the time. Win 2k3 is announcing itself in such a way that before the 'restrict' we tried peering with it. Not sure why this wasn't an issue with 4.1.1 Now we simply reply and take no further action. 16:13:30.023910 202.50.245.234.2823 > 130.123.2.99.ntp: v3 sym_act strat 0 poll 17 prec -6 16:13:30.023960 130.123.2.99.ntp > 202.50.245.234.2823: v3 sym_pas strat 2 poll 17 prec -17 (DF) [tos 0x10] -- .*. | Glen Eustace, Infrastructure Development Engineer /V\ | Information Technology Services PN460, Turitea, (/ \) | Massey University, Palmerston North, New Zealand. ( ) | Ph: +64 6 356 9099 x 81005, Fax: +64 6 350 5607, Mob: +64 27 450 0321 ^^-^^ |------------------------------------------------------------