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Auteur: Hendrik Boom
Date:  
À: dng
Sujet: Re: [DNG] Request for information - - re: networking
On Sun, Jun 04, 2023 at 08:48:00PM -0500, o1bigtenor via Dng wrote:
> On Sun, Jun 4, 2023 at 6:24 PM Ralph Ronnquist <rrq@???> wrote:
> >
> > On Sun, Jun 04, 2023 at 05:08:13PM -0500, o1bigtenor via Dng wrote:
> > > Greetings
> > >
> > > This group has so far shown a very large AND a very deep knowledge
> > > base in most anything I've ever thought connected to computers and
> > > computing.
> > >
> > > I'm trying to educated myself on networking and am finding, so far at
> > > least, that this is considered specialist only country. So when I
> > > start asking questions I get ignored because my questions are too
> > > basic (so they're considered boring) yet I can't find answers.
> > >
> > > I'll start with one question I'm grappling with at moment.
> > >
> > > Working on developing a networking system where there are a very large
> > > number of sensors/inputs.
> > > Trial version will have some at least 4 if not six such for one
> > > 'stall'. That's to make sure I can do what it is that I want to do.
> > > Version 1 would have 12 'stalls' so that at least 50 odd sensors/systems.
> > > (looking at having other functions so I'm loathe to think a limit of
> > > 'only' a couple hundred information points - - - that's for version
> > > 1(!!).)
> > > Version 2 could have anywhere from 50 odd to almost 200 discrete
> > > 'stalls' - - - this is not a this year project but, hopefully, not too
> > > far away.
> > > (This would mean that 1500 to 2000 sensor/system points is not too far
> > > into the future.)
> > >
> > > So I've been thinking of using a 172.16.x.x network rather than a
> > > 192.168.x.x as it would seem to me that I can easily put over 300
> > > sensors/systems on a 172.16.x.x system and I would need to be using
> > > some kind of system of cascading routers to use a 192.168.x.x .
> > >
> > > There is a change in ISP coming and I'm working on setting up a
> > > opnsense router/firewall - - - at present I'm on fixed wireless (quite
> > > pathetic internet service actually and far far too expensive for what
> > > I get!!) but that change is still some time away - - - at least a few
> > > weeks and maybe even a few months.
> > >
> > > Should I switch my present router from 192.168.1.1 to my chosen
> > > 172.16.x.x (I'm running on dd-wrt)?
> >
> > It's really the netmask, or number of fixed bits, that determines the
> > span of IP addresses you have on a network. An IP address is 32 bits,
> > and the prevailing convention is to have the higher order bits fixed,
> > so as to form an enmeration space of the the lower order bits for
> > enumerating the hosts. (And by convention the highest and lowest
> > numbers in a space are "reserverd" to be "broadcast address" and
> > "network address" respectively).
> >
> > By convention home routers use a 24 bit netmask by default, but most
> > routers have a programmable netmask and it's your choice what to use.
> >
> > By agreement the whole 192.168.0.0/16 is considered a "private IP
> > space" that is not supposed to be routed on internet.
> >
> > Thus, you may well keep 192.168.1.1 as router address, but change its
> > /24 (or 255.255.255.0) to eg. /20 (or 255.255.120.0) to give yourself
> > 16 time more addresses on your network (i.e 4094 hosts + broadcast +
> > network).
> >
> > If you go for 172.16.x.x you probably mean 172.16.x.x/12 (or netmask
> > 255.120.0.0).. i.e. IP addresses that are all same in the 12 highest
> > bits, and allowing for 20 bits to host enumeration (plus "broadcast"
> > and "network").
> >
> > That IP space is similar to 192.168.0.0/16 in being an agreed
> > "private" address space, although 16 times larger address space.
>
> So if I wanted I could have 192.168.0.0/12 and I have the same address
> space as in 172.16.x.x/12?
> >
> > Those address space agreements are handled globally by IETF
> > (https://www.ietf.org/). Conventions are what they are and they show
> > up in various ways in user interfaces and programs.
> >
>
> This is where ipv6 would be useful but its going to be a while before
> my isps are getting there - - - my guess is at least a couple years if
> not longer!
>
> Hmmmmmmmmmm - - - - is there anything else that might be different
> between using 192.168.x.x and 172.16.x.x ?


A lot of coffee shops use 192.168.x.x for their clients.
If you're going to set up all your equipment in one of those coffee shops
you might have difficulties.
(unlikely scenario, I think, but then you haven't told me where you're setting all this up!)

-- hendrik

>
> (Anything obvious at least - - - - )
>
> TIA
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