Obiviously it's network part that would be considered peifix in above example..
for your second oqestion..
Remeber that number of on bit in subnet mask represent the network and off bit represent hosts
in your classless case you have 19 bits on in the subnet so according that your 1st subnet range will be
172.22.0.0 to 172.22.31.255
now the range from 172.22.0 to 172.22.31 would be your prefix..
I am trying to make in binary,
2^5 = 32 (from 0 - 31)
so that number which is in red will specify the prefix ! right ?
172.22.0.0 - 172.22.31.255
in if we take another example
this will be
2^0 = 1
the red color is the prefix
so my outcome is, if it is classless then the prefix will be address range not only the address ! right ?
prefix is just the number of 1's in the subnet mask
if there are 8 1's then the prefix is 8
27 1's then the prefix is 27
has a prefix of 25
has a prefix 0f 16
so prefix is really network + subnet part of an address
as for network address
it depends on the context
if they are referrring to the classful network
address or the subnet network address
network address is 10.2.2.0
but classful network address is 10.0.0.0
and thats about it
CIDR as a technology is much more than the concept of a prefix that is created at any bit position, but yeah, you are right, because without that ability, there would be no CIDR.
And its usually referred to as "CIDR notation" (older terminology) in the form IP ADDRESS + PREFIX, eg 10.1.1.1/18, or simply "slash".
"Prefix" is becoming the general umbrella term these days, and it is used commonly in BGP.
its the prefix....25
cidr is classless inter domain routing.....and in my opinion is usually a term used for public addressing. used by isps for bgp ...and route aggregation.
where the isp breaks a network into different prefixes and distributes subnets of the network to clients and then groups these subnets ( summarizes ) them out to the internet.
for me its always better to referr to private addresses as classful and classless with a prefix of xyz
i dont mention the term cidr unless im dealing with the internet at large and public external networks..
so if you were working on an enterprise network and started discussing cidr..for internal subnetting...maybe it would seem a bit confusing
if you get me.
imo ...cidr should be reserved for speaking about BGP and the main core routing tables and isps and the like ( the big stuff )
the breakup of addresses handed down from ip distributors to isps
not for private addressing with your little rip routing protocol and your 2600 second hand router from ebay., and your homemade ethernet cable that your mum had when she bought a lap top from wall mart ( buy one get one free ).....for her birthday.
sorry im humoring myself...dont be offended.