Solved Why should be network defined as ending with 0?

[CaffeineAddict]

OK this is noob's question because it was long time ago when I learned this...

Let's say your local IP is 10.10.10.10
Let say default gateway is at 10.10.10.1
Let's say subnet mask is 255.255.255.0

Then why should this "network" be classified as Network 10.10.10.0/24? why not 10.10.10.1/24?

 

[osprey]

OK this is noob's question because it was long time ago when I learned this...

Let's say your local IP is 10.10.10.10
Let say default gateway is at 10.10.10.1
Let's say subnet mask is 255.255.255.0

Then why should this "network" be classified as Network 10.10.10.0/24? why not 10.10.10.1/24?

With a /24 subnet mask, all IP addresses from 10.10.10.0 to 10.10.10.255 are in the same subnet, and 10.10.10.0 is the network address while 10.10.10.255 is the broadcast address for that subnet. They are the reserved addresses, whereas 10.10.10.1 is an optional ip address for a machine within the network. The /24, as I guess you know, is the "Classless Inter-Domain Routing" notation which indicates that the first 24 bits of the IP address (reading from leftmost to right, 8 bits per section between the dots) are used for the network portion of the address, (masking them) while the remaining bits are used for host addresses within that network.