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This question is more a question of definition then a technical one:

You have some network with the network identifier 172.16.0.8 and a subnet mask 255.255.255.248 (/29)

We know that the usable address range is 172.16.0.9-172.16.0.14.

If I say e.g. 172.16.0.10/29, do I mean the whole subnet or the specific IP address 172.16.0.10 with a subnet mask 255.255.255.248?

Is "IP Address" the correct term for the combination (IP with CIDR)? What is the most compact way to express this construct?

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I’d say it depends on the context of the conversation.

If someone asks you what the IP address of a host is and what the mask is, and you respond with 172.16.0.10/29, that answers both of their questions at the same time.

If someone asks you what the subnet is, and you say 172.16.0.10/29, you’d be misspeaking but the /29 would still answer their question if they know how subnet calculations work and correct it to 172.16.0.8/29.

If someone only wants to know the host IP address, you would instead say 172.16.0.10 or 172.16.0.10/32.

There’s really no purpose to telling someone a mask or CIDR notation if they only need the host IP address since the size of the network the host is a member of is irrelevant.

So, I’d say only state the CIDR notation in cases where the size of the network is relevant, and you’d say it like “the network is ‘blah’, and the CIDR notation is ‘blah’.”, or numerically like you said above (172.16.0.8/29). Some people do just call it “the CIDR” or “CIDR mask”. I don’t know that there is a technically correct name, honestly. Even calling it “CIDR notation” is not official - it’s just what it’s commonly called.

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