Hi, thank you for the great resource, I love the clarity and simplicity without the useless "filler" material to artificially increase a book's number of pages.
I looked up the section on classful networking and CIDR and would like to make one addition that is often overlooked: in classful networking, not only are the network sizes fixed, but also where they reside in the IP address room.
E.g., class A networks used 0.0.0.0 – 127.255.255.255 whereas class C networks used 192.0.0.0 – 223.255.255.255.
With CIDR notation, not only can you have networks of different size, but they can start at arbitrary addresses.
If people talk about a class C network today, they often falsely relate to a network with 256 addresses - but which is located in the address room of original class A/B/D/E networks, for example.
I looked up the section on classful networking and CIDR and would like to make one addition that is often overlooked: in classful networking, not only are the network sizes fixed, but also where they reside in the IP address room.
E.g., class A networks used 0.0.0.0 – 127.255.255.255 whereas class C networks used 192.0.0.0 – 223.255.255.255.
With CIDR notation, not only can you have networks of different size, but they can start at arbitrary addresses.
If people talk about a class C network today, they often falsely relate to a network with 256 addresses - but which is located in the address room of original class A/B/D/E networks, for example.