Question about CIDR notation and subnets

Juddog

Diamond Member
Dec 11, 2006
7,851
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If you had a network with the following CIDR mask:
192.168.0.1/23

That would mean the network ID would be 192.168.0.0, and the broadcast would be 192.168.1.255.

Would that allow for an IP address to be assigned and still be usable for 192.168.0.255 and 192.168.1.0, or is there some other hidden rule that doesn't allow you to use these addresses?
 

ScottMac

Moderator<br>Networking<br>Elite member
Mar 19, 2001
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While "legal," addresses ending in 255 or 0 are usually avoided by convention.
There are folks (unfortunately) that will see those addresses and "correct" them ... they're the same folks that "fix" the subnet mask back to its "proper" 255.255.255.0 value.

Addresses like that are on / were on some of the Cisco exams (where .255 is not a broadcast and .0 is not a "network address").
 

Juddog

Diamond Member
Dec 11, 2006
7,851
6
81
While "legal," addresses ending in 255 or 0 are usually avoided by convention.
There are folks (unfortunately) that will see those addresses and "correct" them ... they're the same folks that "fix" the subnet mask back to its "proper" 255.255.255.0 value.

Addresses like that are on / were on some of the Cisco exams (where .255 is not a broadcast and .0 is not a "network address").

Ahh ok thank you for the answer!