I don't understand this whole CIDR notation thing, help me out

[InorganicMatter]

Not a homework problem, just tinkering with this IP stuff.

My network is all 192.168.0.something. The router/gateway (cheap Netgear) is 192.168.0.1, and the DHCP scope is from 192.168.0.2 through 192.168.0.50. IPconfig says my subnet is 255.255.255.0. What would my CIDR notation be? Would it be 192.168.0.1/24?

Any and all help is greatly appreciated.

 

[goodcooper]

we just call that 'slash notation'... but i guess you could refer to it as a classless interdomain routing 'notation' (makes less sense to me)

but i mean, what are you trying to notate? your router? i guess you could say 192.168.0.1/24... but if you were trying to 'notate' your network, i think 192.168.0.0/24 would be more correct...

the /24 is just how many bits you have in your subnet...

if your mask is 255.255.255.0

in bin it would be

11111111.11111111.11111111.00000000

so there are 24 1s

11111111.11111111.11111111.11100000 is a /27

so you would have a mask of 255.255.255.224 (224 = 128 + 64 + 32)

see?

 

[InorganicMatter]

Got it. I'm trying to indicate my entire network, so I would use 192.168.0.0/24. Thanks.

 

[goodcooper]

bingo , 192.168.0.1 is just the first address (coincidentally one used by the router port)