Why can't you use 1.0.0.0/8?

Question

Computer networks

Why is it impossible / not recommended to use local addresses like 1.0.

There are answers that these addresses have already been occupied half a century ago by the cunning American military, who naturally do not respond, so if you still use these addresses and go online, something incomprehensible and bad will happen.
I even read that the packet exchange rate in the LAN can drop to 10Mbps.

Strange as it may seem, the question is not popular on the network. Help me get a humanitarian answer to it :)

Answer 1

Why not? Can.
It's just not recommended because special bands have been allocated for LANs. If you follow the recommendations and standards, firstly, you will not get into a situation where the question is not popular on the network, and secondly, if your local area goes online, there will be no problem with the real owners of IP addresses.

Answer 2

For the same reason that you cannot give yourself an arbitrary address on the local subnet - the answer to it will go where it should go according to the configurations of the routers.
Also, 1.0.0.0/8 is Australia :)

Answer 3

Because this is at least a block of white IPs routable in the global network, in principle, for a test in a local. You can assign them

Answer 4

I will support Saboteur .
Nobody forbids you to use this block inside your local network, as you wish.
If you are sure that you and your users will not access external servers located in Australia, then in principle you will not have any problems.