How big a network is routed these days?

David Freedman david.freedman at
Wed Jan 17 17:19:46 UTC 2007

I'm interested as to why RIRs dont set the minimum PI allocatable
to /24 in order to fit with the current trend.

I mean, I can see the reason for smaller allocations where an LIR routes 
and aggregates both but these are rare and probably legacy examples.

Changing the allocation policy such that a /24 minimum exists for PI 
would be a good thing IMHO, forcing people to either apply for portions 
of PA space from LIRs (and having LIRs do what they should be doing)
  or lie through their teeth to get a /24 (but then not try and wonder 
why anything smaller is not routed correctly)

Of course I'm probably opening the proverbial can of worms about who 
should or shouldn't apply and how they do, but I do find the possibility 
of obtaining a sub /24 PI allocation a little odd in this day and age.


Justin M. Streiner wrote:
> On Wed, 17 Jan 2007, John Smith wrote:
>> my organization is considering PI addresses as a way to multihost.
>> Having read the archives regarding disadvantages and alternatives,
>> my question is how big a network must one have to be reasonably
>> sure the BGP routers will accept the route?
> A /24 is the smallest block of IPv4 addresses that you can reasonably 
> expect to be globally reachable.  Depending on where you're located, the 
> different address registries (ARIN, RIPE, APNIC, etc...) have different 
> policies regarding the smallest PI block they'll allocate to end users.
> jms

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