Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1986-2001 Microsoft Corp. C:\WINDOWS>netsh ras ip set negotiation ?
set negotiation [mode = ] ALLOW|DENY
Specifies whether the RAS server will allow IP to be configured for
any client connections it accepts.
mode - the mode
ALLOW - permit IP over client connections.
DENY - do not permit IP over client connections.