Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1986-2001 Microsoft Corp. C:\WINDOWS>netsh interface ipv6 delete neighbors ?
Usage: delete neighbors [[interface=][[address=]]]
interface - Interface name or index.
address - Address of neighbor.
Remarks: Flushes the neighbor cache. If an interface is specified,
flushes the cache only on that interface. If an address is
also specified, deletes only that neighbor cache entry.
delete neighbors "Private"