Smallest RIPE NCC Allocation / Assignment Sizes
 
Joćo Luis Silva Damas 
Leo Vegoda 
RIPE NCC 
Document ID: ripe-328 
Date: August 2004 
Obsoletes: ripe-222, ripe-242, ripe-259, ripe-264, ripe-266, ripe-269, ripe-289, 
ripe-295, ripe-296, ripe-299, ripe-319, ripe-325, ripe-326
 
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. 
IPv4 CIDR block 
Smallest RIPE NCC
Smallest RIPE NCC 

Allocation
Assignment 
62/8 
/19 
/19 
80/8 
/20 
/20 
81/8 
/20 
/20 



82/8 
/20 
/20 
83/8 
/21 
/21 
84/8 
/21 
/21 
85/8
/21
/21
86/8
/21
/21
87/8
/21
/21
88/8
/21
/21
193/8 
/19 
/29 
194/8 
/19 
/29 
195/8 
/19 
/29 
          196.200/13
/20
/24
212/8 
/19 
/19 
213/8 
/19 
/19 
217/8 
/20 
/20 
 
IPv6 CIDR block 
Smallest RIPE NCC
Smallest RIPE NCC 
  
Allocation
Assignment 
2001:0600::/23
/35 
/48
2001:0800::/23 
/32
/32
2001:0A00::/23 
/32
/32
2001:1400::/23 
/32
/32
2001:1600::/23
/32
/32
2001:1A00::/23
/32
/32
2001:1C00::/22
/32
/32
2001:2000::/20
/32
/32
2001:3000::/21
/32
/32
2001:3800::/22
/32
/32
2001:4000::/23
/32
/32
2001:4600::/23
/32
/32
 
Table 1. Allocation/Assignment sizes in CIDR blocks held by the RIPE NCC.