Subject: Tool that says whether IP addresses are routable or reserved

From: Andre Majorel <[email-masked]>
Date: Sat, 10 Sep 2016 19:36:11 +0200

Is there a tool which would take IPv4 addresses on the command
line and say whether or not they are regular and routable ?

host(1) is not very useful for that as it doesn't seem to
distinguish between an address which happens not to used by a
domain name at this time (eg 9.9.9.9) and one which could never
be (eg 192.168.0.1).

Thanks in advance.

-- 
André Majorel <http://www.teaser.fr/~amajorel/>
alias reportbug='cat >/dev/null'

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From: Joe <[email-masked]>
Date: Sat, 10 Sep 2016 19:22:22 +0100

On Sat, 10 Sep 2016 19:58:50 +0200
<[email-masked]> wrote:

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> On Sat, Sep 10, 2016 at 07:36:11PM +0200, Andre Majorel wrote:
> - From your question I'm not sure this is the answer you are looking
> for, but I'll give it a try. According to RFC 1918 [1], the following
> address ranges are reserved for "private use":
> 
>      10.0.0.0        -   10.255.255.255  (10/8 prefix)
>      172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
>      192.168.0.0     -   192.168.255.255 (192.168/16 prefix)
> 
> Note that this is for IPV4, IPV6 is probably a bit more complex :-)
> 
There are a lot more reserved for other unspecified reasons. The list
of more than 165,000 address blocks here http://software77.net/geo-ip/
contains quite a few listed 'reserved'. The list is frequently updated.

-- 
Joe

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From: Henrique de Moraes Holschuh <[email-masked]>
Date: Sat, 10 Sep 2016 16:23:01 -0300

> contains quite a few listed 'reserved'. The list is frequently updated.

https://tools.ietf.org/html/rfc6890

http://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml

http://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.xhtml

These are canonical and authoritative.

IPv6 has them, too:

http://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml

http://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xhtml

There are also the registries for multicast space, etc.

-- 
  Henrique Holschuh