(even if there are a large quantity of valid hosts that go unused)
I’ve been trying to understand IP addresses and subnet masks and I watched (and understood) the majority of this video https://youtu.be/s_Ntt6eTn94. This was a question I had at the end though. Is there some sort of disadvantage of having a class A subnet?
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If it’s for a private local network, you absolutely can.
There’s one class A network – 10.0.0.0/8 – that’s reserved as non-routable.
This means it doesn’t exist on the internet – you try to send a packet to it over your internet link, your router will say lol no.
As such, that entire network is always available for *local* LAN addresses; they’ll never conflict with a real internet address. You can put every machine in your organization (assuming you have less than 16 million of them) in that address space and they’ll always be free to use – you just can’t reach them from outside, or reach the outside world from them without using NAT or such.
But any other class A? There’s only 256 of the things, and there’s not many people or organizations that have the money and clout to own 1/256th of *the entire internet* for their own personal sandbox.
That’s why.
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