from http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B813878
For example, to block network traffic from any IP address and any source port to destination port UDP 1434 on a Windows 2000-based computer, type the following. This policy is sufficient to protect computers that run Microsoft SQL Server 2000 from the "Slammer" worm.
ipsecpol -w REG -p "Block UDP 1434 Filter" -r "Block Inbound UDP 1434 Rule" -f *=0:1434:UDP -n BLOCK -x
For example, to block any network traffic that originates from your Windows 2000-based computer that is directed to UDP 1434 on any other host, type the following. This policy is sufficient to prevent computers that run SQL Server 2000 from spreading the "Slammer" worm.
ipsecpol -w REG -p "Block UDP 1434 Filter" -r "Block Outbound UDP 1434 Rule" -f 0=*:1434:UDP -n BLOCK
get this col tool from: http://www.microsoft.com/windows2000/techinfo/reskit/tools/existing/ipsecpol-o.asp