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Re: ping to non-existent addresses on the local loopback succeed!

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Charles T. Smith wrote:
> On Wed, 02 Nov 2016 16:26:58 +0100, Carlos E.R. wrote:
>
>> On 2016-11-02 16:19, Charles T. Smith wrote:
>>> Can someone explain to me why?
>>>
>>> E.g.
>>>
>>> $ ping 127.0.2.1 PING 127.0.2.1 (127.0.2.1) 56(84) bytes of
>>> data. 64 bytes from 127.0.2.1: icmp_seq=1 ttl=64 time=0.064 ms
>>> ...
>>
>> Works as expected. All 127.*.*.* addresses do exist.
>
> Thank you.
>
> But why?
>
> Where would I look for an explanation of that?
>
> Is there a keyword for that phenomena that I can use to search the
> internet?

https://en.wikipedia.org/wiki/Localhost

"The IPv4 loopback addresses are reserved within the IPv4 namespace by
the IETF Special Use IPv4 Addresses standard (RFC 5735).[4] The
reservation can be traced back to the November, 1986 Assigned Numbers
standard (RFC 990), which was issued at a time when the first byte of
the IP address was a signed network number that was the only portion of
the address assigned by the IETF. Reserving its highest possible network
number (127) for loopback testing eventually resulted in the excessive
reservation of 16,777,214 loopback addresses."

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Thread

ping to non-existent addresses on the local loopback succeed! "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2016-11-02 15:19 +0000
  Re: ping to non-existent addresses on the local loopback succeed! "Carlos E.R." <robin_listas@invalid.es> - 2016-11-02 16:26 +0100
    Re: ping to non-existent addresses on the local loopback succeed! "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2016-11-02 15:39 +0000
      Re: ping to non-existent addresses on the local loopback succeed! Andy Furniss <spam@spam> - 2016-11-02 15:52 +0000
        Re: ping to non-existent addresses on the local loopback succeed! "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2016-11-02 16:32 +0000
    Re: ping to non-existent addresses on the local loopback succeed! Pascal Hambourg <pascal@plouf.fr.eu.org> - 2016-11-03 07:41 +0100
      Re: ping to non-existent addresses on the local loopback succeed! "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2016-11-03 08:51 +0000

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