From: Theodore TZEVELEKIS (theodore_tzevelekis@xxxxxxxxx)
Date: Thu May 17 2001 - 13:42:15 GMT-3
It is 16 mil :-)
And, may I add, Class B is 65K (65536 to be exact)
Which adds up to just over 1 trillion addresses with
NAT (1.099.511.627.776
to be exact), minus a few thousand here and there for
connectivity and misc
uses. Let's say 100 billion IP addresses for
connectivity. I think that
should be enough :-)
Wich leaves uses with just under 1 trillion addresses.
Now if for every class B private address you use a
full class C private
address range and NAT it, you can multiply this number
by another 65536
(256*162.168.x.0/24=65536) you end up with
72.057.594.037.927.936
Now after leaving a 57.594 trillion IP addresses for
interconnection, you
still have a little over (something like 32 million
over) 72.10E15 (does
this number even have a name???????) IP addresses to
use.
Now, Bruce, if you need more than this, I suggest that
your company pays to
buy a class A address.
I'm sorry for being sarcastic. I just want to point
out that you can have as
many IP addresses as you like with careful planning
and good design. And
leave plenty of room for expansion.
Oh, and of course, all these addresses can use dynamic
NAT to connect to the
internet.
PS: disclaimer: All these numbers are approximative
:-)
Theo
--- "Jeff K." <jeffbk@austin.rr.com> wrote:
> Out of curiosity, how do you all keep getting 65
> million? To me, 2 to the
> 24th power is 16 million (16777216 to be exact).
>
> -Jeff
> ----- Original Message -----
> From: "Walter Chen" <wchen@iloka.com>
> To: "'Andrew Lennon'" <andrew.lennon@nscglobal.com>;
> "Bruce Williams"
> <bruce@williamsnetworking.com>;
> <ccielab@groupstudy.com>
> Sent: Thursday, May 17, 2001 10:16 AM
> Subject: RE: Using Public Addresses Internally
>
>
> > Bruce,
> >
> > One Class A such as 10.0.0.0/8 contains 65 million
> addresses. With all
> kinds
> > of subletting, you can still get millions of
> addresses out of just one
> Class
> > A. Then you can use the 172.16.0.0-172.32.0.0/16
> Class B private space
> > which has about a million addresses. I guess any
> single business won't
> need
> > more than a few million addresses all at once.
> Besides, you can NAT one
> > private space into another private space (say for
> local subnets, use
> > 192.168.0.0/16, and NAT them into 10.0.0.0/8 for
> national use), then you
> can
> > have 65 million NATed subnets each may contain up
> to a million addresses.
> > So, you can use the current private IP scheme to
> create a few trillion
> > addresses for internal use. If this is still not
> enough, you may THEN
> > consider using public addresses.
> >
> > Walter
> >
> > -----Original Message-----
> > From: Andrew Lennon
> [mailto:andrew.lennon@nscglobal.com]
> > Sent: Thursday, May 17, 2001 10:19 AM
> > To: Bruce Williams; ccielab@groupstudy.com
> > Subject: RE: Using Public Addresses Internally
> >
> >
> > Bruce,
> >
> > A couple of things spring to mind:
> >
> > Use the RFC1918 address 10.0.0.0 /8. This is
> "class A" so you will have
> the
> > amount of adresses compared to using a globally
> routable address.
> >
> > If you use an address range in use elsewhere, then
> you are heading for
> > problems if you ever wish to connect to the net.
> >
> > Say your organisation uses the address 47.0.0.0/8,
> and your routers point
> to
> > adresses in this range to base stations etc. What
> happens when someone in
> > your organisation wants to connect to an address
> where the legitimate
> > address is 47.1.1.1? Your routers will route
> towards a base station and
> not
> > the correct host and vice versa.
> >
> > I know you say that there will not be a direct
> Internet connection, but
> you
> > never know what the future may hold....
> >
> > There is no real reason or excuse not to use the
> 10/8 range, after all it
> > was set aside for use exactly for things like your
> organisation's
> > circumstances. Even if 10/8 is already in use at
> your place, I am sure
> that
> > you would be able to use a subset of it in your
> grand scheme.
> >
> > Andy
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com]On Behalf Of
> > Bruce Williams
> > Sent: 17 May 2001 14:56
> > To: ccielab@groupstudy.com
> > Subject: Using Public Addresses Internally
> >
> >
> > My company wants to use public addresses from the
> Class A range
> internally.
> > I
> > realize the danger if these routes got advertised
> on the Internet, but is
> > this
> > something that is considered acceptable if it is
> carefully done to prevent
> > the
> > risk of these routes being propagated out on the
> Public Internet? These
> > networks will be used to address equipment in a
> multitude of cellular
> radio
> > base stations around the country and they will
> only be connected to our
> > network. There will central locations where users
> from the internet could
> > access a database which will query these systems,
> but there will not be a
> > direct internet connection. I would appreciate any
> advice on this.
> >
> > Thanks,
> >
> > Bruce Williams
> > 215-275-2723
> > bruce@williamsnetworking.com
> > **Please
> read:http://www.groupstudy.com/list/posting.html
> > **Please
> read:http://www.groupstudy.com/list/posting.html
> > **Please
> read:http://www.groupstudy.com/list/posting.html
> **Please
> read:http://www.groupstudy.com/list/posting.html
>
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