On Fri, 09 February 2001, "Roisman, Dani" wrote:
A parent organization has an unused /16 of address space, for arguments sake, let's say it's 172.16.0.0/16. It's out of the old "class B" address range. Two groups within the organization want to bring up independant Internet datacenters, and need /18 of address space, each. Since the parent organization owns an unsed /16, the IP registry refuses to give the child organizations any address space - they insist all address blocks assigned to the parent organization be used, first.
ISPph (ph=pigheaded) has a BGP policy that filters out all routes in 128.0.0.0/2 longer than /16.
Return the 172.16.0.0/16 block to the registry (ARIN, APNIC, RIPE or if no one else IANA) and apply for multiple appropriately sized CIDR blocks under the current registry allocation guidelines.