Smallest RIPE NCC Allocation / Assignment Sizes	 
 
Jo�o Luis Silva Damas 
Leo Vegoda 
RIPE NCC 
Document ID: ripe-326 
Date:  June 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

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