The assignment of numerical addresses for Domain Names ??

[Patrick O'Callaghan]

On Thu, 2008-08-07 at 21:20 -0400, William Case wrote:
> Hi;
> 
> My question is quite narrow.  I am not looking for generalized
> explanations of IPv4.  
> 
> When ARIN (American Registry for Internet Numbers or one of its clients,
> or any other IANA RIR) assigns a /8, or /16 number and registers a new
> domain name is there any rules, policy or usual practice in the
> assignment that gives a hint to the nature of the entity that has
> received a certain address?  
> 
> E.g. If I see 64.71.255.198, could I reasonably say "That's a name
> server, or, that's a Rogers Cable Inc. address" or glean any other
> information about the organization, company or purpose?  Or are all such
> address assignments simply arbitrary?  If there is such a rule, policy
> or usual practice, do you know where I could find it and/or see a table
> of such assignments.

Some policy is documented at http://www.arin.net/policy/nrpm.html for
example, but in general you can't look at a random IP number and tell
what it stands for without further investigation. Use "whois" to find
out about specific assigned numbers.

Registries tend to assign blocks of addresses according to some estimate
of future needs, but of course this has varied a lot historically, which
is why early users such as MIT have /24 spaces (what used to be called
Class A). Think about it: MIT has 1/256th of all possible IPv4 addresses
in the world!

IPv6 of course is a whole new ball game, since the space is so large it
allows several alternative policies to exist side by side.

poc