Nope, 10.8.0.0/24
doesn’t fall into 10.0.0.0/16
. AWS is correct, sorry 🙂
In your 10.0.0.0/16
you can create subnets between 10.0.0.0/24
to 10.0.255.0/24
, e.g. 10.0.8.0/24
would work.
Let’s say we’ve got CIDR address 10.20.30.40
– that can fall for example into these subnets:
10.0.0.0/8
– /8 means only the first byte (10.) in the address is the network address.10.20.0.0/16
– /16 means the first two bytes (10.20.) are network.10.20.30.0/24
– /24 means the first three bytes (10.20.30.) are network.10.20.30.40/32
– /32 covers the whole address (10.20.30.40) and sometimes this notation is used to explicitly say it’s a host address. AWS uses that a lot.
Hope that helps 🙂