Stupid Question maybe?

Tue Dec 18 05:45:03 UTC 2018

You may find this helpful in your search for knowledge:

https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing

"Classful" networking is rarely useful other than for understanding How We
Got Here.

There's a handy table in the linked article which expresses each IPv4 mask
length in relation to how many A, B, or C networks it is.

jermudgeon

On Mon, Dec 17, 2018 at 8:37 PM Joe <jbfixurpc at gmail.com> wrote:

>
> Apologizes in advance for a simple question. I am finding conflicting
> definitions of Class networks. I was always under the impression that a
> class "A" network was a /8 a class "B" network was a /16 and a class "C"
> network was a /24. Recently, I was made aware that a class "A" was indeed a
> /8 and a class "B" was actually a /12 (172.16/172.31.255.255) while a
> class "C" is actually a /16.
>
> Is this different depending on the IP segment, i.e. if it is part of a
> RC1918 group it is classed differently (maybe a course I missed?) Or aren't
> all IP's classed the same.
> I was always under the impression, /8 = A, /16 = B, /24=C, so rightly, or
> wrongly I've always seen 10.x.x.x as "A", and 192.168.x.x as "B", with
> 172.16/12 as one that just a VLSM between the two.
>
> Again, apologizes for the simple question, just can't seem to find a solid
> answer.
>
> Happy holidays all the same!
> -Joe
>

-- 
Jeremy Austin
jhaustin at gmail.com

(907) 895-2311 office
(907) 803-5422 cell
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