This document details the smallest allocations and assignments made by the RIPE NCC to Local Internet Registries (LIRs) and End Users from IPv4 and IPv6 CIDR blocks allocated to the RIPE NCC by the Internet Assigned Numbers Authority (IANA) and other registries.

"Smallest allocation" refers to the smallest allocation made to LIRs by the RIPE NCC.

"Smallest assignment" refers to the size of the smallest assignment made by the RIPE NCC to an End User.

Small IPv6 blocks have been assigned to Internet Exchange Points (IXPs) under the interim policy allowing this.

From October 2003, IPv4 allocations and assignments to LIRs and End Users in African countries north of the equator will be made from 196.200.0.0/13. This range is part of a /8 block also used by the American Registry for Internet Numbers (ARIN) for African allocations. Because the longest prefix ARIN allocate or assign for 196/8 is /24 this is also the longest prefix the RIPE NCC will assign from 196.200.0.0/13.

Routing decisions for blocks of address space are the sole responsibility of network operators. However, network operators taking routing decisions based on prefix length are requested and encouraged to route at least blocks of sizes corresponding to the "smallest allocation" and larger.

Users receiving networks smaller than the smallest allocation size are always notified that network operators throughout the Internet may choose not to route, or may filter, these networks.

Table 1. Allocation/Assignment sizes in CIDR blocks held by the RIPE NCC.

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