Re: question about net address

From	David Christensen <dpchrist@holgerdanske.com>
Newsgroups	linux.debian.user
Subject	Re: question about net address
Date	2023-03-19 23:20 +0100
Message-ID	<Gb9xD-dEJf-3@gated-at.bofh.it> (permalink)
References	<GaCV3-dkb8-5@gated-at.bofh.it> <GaN45-dqtO-1@gated-at.bofh.it> <GaOjv-drce-1@gated-at.bofh.it> <GaY9b-dxET-1@gated-at.bofh.it> <GaYsx-dxM7-3@gated-at.bofh.it>
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On 3/19/23 03:28, coreyh@free.fr wrote:
> On 19/03/2023 18:00, David Christensen wrote:
>> On 3/18/23 16:31, coreyh@free.fr wrote:
>>> On 19/03/2023 06:17, Kushal Kumaran wrote:
>>>> On Sat, Mar 18 2023 at 07:28:23 PM, coreyh@free.fr wrote:
>>>>> Hello
>>>>>
>>>>> I know 192.168.1.0/24 is a valid C range for network address.
>>>>>
>>>>> but what does 192.168.1.1/24 mean?
>>>>>
>>>>> I ask this just for a setting in the SPF:
>>>>>
>>>>> spf.pinoad.se.        300    IN    TXT    "v=spf1 
>>>>> ip4:188.66.63.1/24 -all"
>>>>>
>>>>
>>>> It means the same thing.  192.168.1.1/24 is the same range as
>>>> 192.168.1.0/24, but written by someone not paying too much attention.
>>>
>>>
>>> That's correct. Thanks.
>>
>>
>> AIUI:
>>
>> * 192.168.1.0/24 identifies an IPv4 network with an address of
>> 192.168.1.0 and a network prefix of 24 bits.  The address is within
>> the reserved private block 192.168.0.0/16.  The prefix corresponds to
>> a class C network.
>>
>> * 192.168.1.1/24 identifies an IPv4 network interface with an address
>> of 192.168.1.1 and a network prefix of 24.  The interface is
>> configured to communicate over the 192.168.1.0/24 network.
>>
>>
>>
> 
> So for Inleed (a local ISP)'s SPF:
> 
> spf.pinoad.se.        300    IN    TXT    "v=spf1 ip4:188.66.63.1/24 -all"
> 
> 
> They specify only 188.66.63.1 to send email?
> 
> But as far as I know their mailserver is 188.66.63.2:
> 
> mail.inleed.xyz.    300    IN    A    188.66.63.2
> 
> 
> Then this mail server should have problems in messages delivery.
> 
> Thanks
> Corey
> 
> 

If I correctly understand Sender Policy Framework SPF Record Syntax:

http://www.open-spf.org/SPF_Record_Syntax/


The phrase "ip4:188.66.63.1/24" in the above DNS SPF record states that 
outgoing mail will come from hosts in the address block 188.66.63.1/24.


The address 188.66.63.2 is within the published address block, so the 
ISP is stating that mail sent by that host is legitimate.


On 3/19/23 03:38, coreyh@free.fr wrote:
 > So,
 >
 > * 188.66.63.1/24 is a range, not a single host in SPF
 > * why it's not written as 188.66.63.0/24 which is more clear?
 >
 > Thanks


I agree that "188.66.63.0/24" would be a more conventional way to 
specify a network address block.  Perhaps you should ask the ISP why 
they used "188.66.63.1/24".


David

Thread

question about net address coreyh@free.fr - 2023-03-18 12:30 +0100
  Re: question about net address Markus Schönhaber <debian-user@list-post.mks-mail.de> - 2023-03-18 13:40 +0100
  Re: question about net address Timothy M Butterworth <timothy.m.butterworth@gmail.com> - 2023-03-18 14:30 +0100
  Re: question about net address Kushal Kumaran <kushal@locationd.net> - 2023-03-18 23:20 +0100
    Re: question about net address coreyh@free.fr - 2023-03-19 00:40 +0100
      Re: question about net address David Christensen <dpchrist@holgerdanske.com> - 2023-03-19 11:10 +0100
        Re: question about net address coreyh@free.fr - 2023-03-19 11:30 +0100
          Re: question about net address Joe <joe@jretrading.com> - 2023-03-19 11:40 +0100
          Re: question about net address Jeremy Ardley <jeremy@ardley.org> - 2023-03-19 11:40 +0100
            Re: question about net address coreyh@free.fr - 2023-03-19 11:40 +0100
              Re: question about net address jeremy ardley <jeremy@ardley.org> - 2023-03-19 11:50 +0100
              Re: question about net address <tomas@tuxteam.de> - 2023-03-19 12:10 +0100
              Re: question about net address Greg Wooledge <greg@wooledge.org> - 2023-03-19 13:20 +0100
                Re: question about net address Curt <curty@free.fr> - 2023-03-19 18:20 +0100
                Re: question about net address David Wright <deblis@lionunicorn.co.uk> - 2023-03-19 19:50 +0100
              Re: question about net address Stefan Monnier <monnier@iro.umontreal.ca> - 2023-03-19 16:00 +0100
            Re: question about net address Yassine Chaouche <a.chaouche@algerian-radio.dz> - 2023-03-19 12:10 +0100
              Re: question about net address <tomas@tuxteam.de> - 2023-03-19 12:20 +0100
              Re: question about net address <tomas@tuxteam.de> - 2023-03-19 12:20 +0100
                Re: question about net address Nicolas George <george@nsup.org> - 2023-03-19 12:20 +0100
                Re: question about net address Jeremy Ardley <jeremy@ardley.org> - 2023-03-19 12:40 +0100
                Re: question about net address Nicolas George <george@nsup.org> - 2023-03-19 12:50 +0100
                Re: question about net address Greg Wooledge <greg@wooledge.org> - 2023-03-19 13:30 +0100
                Re: question about net address David Wright <deblis@lionunicorn.co.uk> - 2023-03-19 18:30 +0100
                Re: question about net address David Wright <deblis@lionunicorn.co.uk> - 2023-03-19 19:50 +0100
                Re: question about net address Jeremy Ardley <jeremy@ardley.org> - 2023-03-20 00:40 +0100
                Re: question about net address fh@dnsbed.com - 2023-03-20 01:30 +0100
                Re: question about net address Stefan Monnier <monnier@iro.umontreal.ca> - 2023-03-21 23:30 +0100
                Re: question about net address Jeremy Ardley <jeremy@ardley.org> - 2023-03-22 00:00 +0100
                Re: question about net address David Wright <deblis@lionunicorn.co.uk> - 2023-03-22 00:50 +0100
                Re: question about net address David Wright <deblis@lionunicorn.co.uk> - 2023-03-22 15:50 +0100
                Re: question about net address Jeremy Ardley <jeremy@ardley.org> - 2023-03-19 12:40 +0100
                Re: question about net address Yassine Chaouche <a.chaouche@algerian-radio.dz> - 2023-03-19 13:10 +0100
                Re: question about net address Curt <curty@free.fr> - 2023-03-19 18:10 +0100
              Re: question about net address fh@dnsbed.com - 2023-03-19 12:40 +0100
                Re: question about net address <tomas@tuxteam.de> - 2023-03-19 13:00 +0100
              Re: artifiial intelligence (was: Re: question about net address) Yassine Chaouche <a.chaouche@algerian-radio.dz> - 2023-03-20 10:30 +0100
          Re: question about net address David Christensen <dpchrist@holgerdanske.com> - 2023-03-19 23:20 +0100
  Re: question about net address Yassine Chaouche <a.chaouche@algerian-radio.dz> - 2023-03-19 10:00 +0100
    Re: question about net address Yassine Chaouche <a.chaouche@algerian-radio.dz> - 2023-03-19 10:10 +0100
    Re: question about net address debian-user@howorth.org.uk - 2023-03-19 17:50 +0100

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