On Sat, 29 May 2004, Scott Harney wrote:

> I can't believe no one answered this yet.  whois.
> 
> As in 'whois ip.ad.dr.ess' . Most linux distributions have a whois
> client either already included or available via a package.

To elaborate a little further on Scott's reply, IP address assignments are 
handled by 4 different registries around the world, similar to how DNS is 
handled.  ARIN (American Registry on Internet Numbers) is the registry in 
the US.  See www.arin.net.  RIPE (www.ripe.net) handles Europe, APNIC 
(www.apnic.net) for Asia, and LACNIC (www.lacnic.net) handles Latin 
America.  The IP registries know all about which ISP owns a specific IP 
address.

Some versions of whois on redhat want you to specify the whois server to
use, like whois [EMAIL PROTECTED]

ARIN also runs the special top level domain in-addr.arpa, which is used 
for reverse DNS lookups.  You may have seen reference to this domain when 
using the host command for a reverse lookup.  Notice the IP is backwards, 
just like the reverse DNS zone file.

[EMAIL PROTECTED]:~$ host 147.174.1.23
23.1.174.147.in-addr.arpa domain name pointer vulcan.csd.selu.edu.

One common mistake people make when changing/moving their nameservers is 
they make appropriate changes to forward DNS records with their registrar, 
but forget to make the same changes with their IP registry.  Then 
reverse DNS breaks, and everything else that depends on it.

> There are alternate traceroute clients which can pull Autonomous System
> numers (BGP) and you can feed those into traceroute as well.

The IP registries also assign ASN's (Autonomous System numbers), which are
used by BGP routers on the internet.  Each autonomous (independent) 
network needs a unique ASN numbers.  If you just have one ISP, you might 
not need an ASN.  But a large org that has multiple ISP's and does BGP 
routing between them probably has an ASN.  At that point they are 
autonomous, independent of any one ISP.

ray

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