What is the most standard subnet length on internet

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1

Hi everyone,

I'm going to rebuild IP allocation policy of my company and I am looking for some standard reference for my policy.
I have already studied some standard like RFC1518, RIPE181, RFC2050 and I got it is very important to maintain hierachy structure.
However, what I am really wondering is what is the most standard subnet length that always can be guaranteed through Internet. less than /24 bit ?
I could not find any documents about that, which subnet length is most proper value and pursue internet standard policy ?

Could anyone give me some information guides ?

Best wishes,
Chiyoung

2

nothing can always be guaranteed in life or the internet.

but /24s do seem to be fairly widely used. so they probably work for
the folk announcing them.

randy

3

Chiyong,

Check out:

http://bgp.potaroo.net/bgprpts/rva-index.html

Since you are on nanog, you probably get the CIDR-REPORT every Friday but if
not, go surf around at http://www.cidr-report.org

Cheers,
Mike

4

Hi everyone,

I'm going to rebuild IP allocation policy of my company and I am looking for some standard reference for my policy.
I have already studied some standard like RFC1518, RIPE181, RFC2050 and I got it is very important to maintain hierachy structure.
However, what I am really wondering is what is the most standard subnet length that always can be guaranteed through Internet. less than /24 bit ?

Depends on how you count it - /24 is definitely the most numerous from where I sit.

You might find this interesting :

http://www.multicasttech.com/status/cidr.html

Regards
Marshall

5

Chi Young, let me clarify one thing here ..

Do you mean IP allocation as in subnet allocation, swipping in apnic
or through a rwhois server etc?

Or do you mean "what is the minimum subnet size I can announce on the
internet and have other providers not drop it on the floor"?

srs

6

while one can get away w/ /24s (if that is all one has) for many places,
  I suspect that there will be increasing pressure to drop more specific
  /24s as folks routing tables grow.

  your question, "...length that can be guaranteed through the Internet."
  argues for fairly short netmasks, e.g. a /16 is likley to be accepted
  by most folks while very short masks, e.g. /8 or smaller are likly to
  be seen with some level of consideration since so very few prefixes of
  that size are likely to be origin-sourced (often proxy aggregates from
  transit parties)...

  as others have pointed out - this "acceptable" value is fluid, changing
  over time and variable between ISPs. Creating a static policy is likely
  to be flawed.

--bill (crawling out from under his rock, blinking in the bright lights)