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Author: Antony Stone
Date:  
To: dng
Subject: Re: [DNG] Request for information - - re: networking
On Monday 05 June 2023 at 18:42:02, o1bigtenor via Dng wrote:

> I think that 192.160.x.x showed up in this thread as a typo.
> Certainly hasn't been in any of my emails!!!!!


No, it isn't a typo.

Ralph Ronnquist mentioned it (correctly) in his second posting, because
192.168.0.0/12 is invalid. As soon as the netmask gets shortened from 16, you
have to make sure that the second byte of the network address matches.

Basically, it's all down to binary notation.

> > The networks themselves (172.17 != 192.168 afterall ;), and total
> > available subnets (for example, there are only 256 /24s in
> > 192.168.0.0/16 vs 4240 in 172.16.0.0.12).
>
> If only I knew or could find out what '!=' meant.?


"Is not equal to".

> Hmmmmm - - - - so if I were monitoring some 3k sensors/points and the
> actual volume of information isn't that high (high for me is say 10 bytes
> every 0.5 seconds per sensor with most being much lower - - - say 6 to 8
> bytes every 2 to 5 minutes) this still can be controlled through 'one'
> point?


You have to take into account the ARP table inside switches (and wireless
access points, if you're even thinking about doing any of this without
cables).

The ARP table matches up MAC addresses (which are the hardware-unique thing
about any networkable device) and the IP address the device has been assigned
at the time.

You *might* find enterprise (ie: expensive) switches which can handle this many
ARP table entries, but there's no way a wireless access point is going to be
able to do that.


Antony.

--
Pretty Good Privacy (PGP) was first released on this day in 1991.
https://en.wikipedia.org/wiki/Pretty_Good_Privacy

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