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



On Sat, 10 Sep 2016 19:58:50 +0200
<tomas@tuxteam.de> wrote:

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> On Sat, Sep 10, 2016 at 07:36:11PM +0200, Andre Majorel wrote:
> > 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).  
> 
> 
> - 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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