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?

Sure, though it'd be called 192.160.0.0/12 (the identity in the first
12 bits and the rest 0), and it would of course also include addresses
outside of the 192.168.0.0/16 block of "private addresses"; i.e all 16
"/16-blocks" from 192.160.x.x to 192.175.x.x.

> >
> > 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!

It's easy enough to tunnel ipv6 through an ipv4 virtual cable onto an
ipv6 internet host (eg $5/month VPS) and in that way become ipv6
connected well before your ISP :) The principles are the same as ipv4
although the ipv6 folks seem to have reinvented the wheels with
different names, maybe just to make life interesting or maybe to make
grounds for new consulting $$...

> Hmmmmmmmmmm - - - - is there anything else that might be different
> between using 192.168.x.x and 172.16.x.x ?
>
> (Anything obvious at least - - - - )

afaik the are technically the same.

Ralph.

> TIA
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