What is the most standard subnet length on internet

Tue Dec 23 00:10:24 UTC 2008

Hi all, 

I appreciate many people gave me advices,
Some of persons asked me about my questions, I'm sorry for that I couldn't reply to everyone.
Because of your help, I could get many opinions and standards regarding IP allocation policy.

by the way, in APNIC's IP allocation sizes policy, there is a comments like below.
"Below are the minimum sizes for allocations and assignments, This information is provided at the request of the ISP community
to assist in filtering policy decisions "
Currently, is there any provider filtering routes under LIR's minimum allocation size such as /22 ? 

Best regards,
=============================================
 Chi-Young Joung
 SAMSUNG NETWORKS Inc.
 Email: lionair at samsung.com
 Tel +82 70 7015 0623, Mobile +82 17 520 9193
 Fax +82 70 7016 0031
=============================================

------- Original Message -------
Sender : Danny McPherson<danny at tcb.net> 
Date   : 2008-12-21 02:42 (GMT+09:00)
Title  : Re: What is the most standard subnet length on internet

On Dec 18, 2008, at 9:43 PM, 정치영 wrote:

> Suresh,
>
> Yes, I guess my concern is close to the second meaning.
>
> It seems so simple. Currently annoucement of /24 seems to be okey,  
> most upstream providers accept this.
> However I wonder if there is any ground rule based on any standard  
> or official recommandation.
> If there is some standardized rule about prefix length to be  
> annouced, I will make my bgp & IP allocation policy of
> each data center of my company, and I will be able to more fairly  
> and squarely speak to my customer like this
> "You have to change your server's IP address if you want move your  
> server to other place"

Some useful guidance is provided here (and in
subsequent references) as well:

An Architecture for IP Address Allocation with CIDR
<http://tools.ietf.org/html/rfc1518>

Classless Inter-Domain Routing (CIDR): an Address Assignment and  
Aggregation Strategy
<http://tools.ietf.org/html/rfc1519>

Network Renumbering Overview
<http://tools.ietf.org/html/rfc2071>

A Framework for Inter-Domain Route Aggregation
<http://tools.ietf.org/html/rfc2519>

HTH,

-danny