Abbreviating an IP range..?

[standardphone]

I want to thank anyone in advance and I apologize if this has been asked/answered somewhere I have been searching with no luck.

I understand CIDR for subnetting etc. 10.100.53.0/24. However I think there is something simple I might be missing or just not understanding or overthinking.

If I have a subnet range say: 10.100.53.1 thru 10.100.55.254 is there a way to abbreviate that in CIDR? Or is it simply just what it is...that range?

Again, thanks to anyone for your time and consideration.

[Karsten Iwen]

It's just a range, nothing more. But ranges could be also aligned at subnet-borders. If you look at the range 10.100.52.1 to 10.100.55.254 it would match the subnet 10.100.52.0/22.

[pwwiddicombe]

There's are lots of subnet calculators out there on multiple platforms.  A little one I happen to have under Android called LANDroid has an IP Calc function (it also pings/subnet scans/DNS lookup, etc.).  Feed in an ip and select a netmask from the dropdown list, and it provides some basic information. 

I.e.     10.15.1.5/26 tells you

first usable 10.15.1.1    last usable 10.15.1.62  broadcast address 10.15.1.63  usable addresses=62

There are others available, but of the "android net tools" I have, it's the only one that happens to have an IP calculator built in.

[Karsten Iwen]

For anyone working in the networking field, my suggestion is always: Don't use subnet calculators. That's something that really can be done in the head without any tools. And every calculation should be taken as a opportunity to freshen up the capability to calculate these.

[standardphone]

Thanks everyone! I face palmed myself as soon as I read your response (Karsten).

Usually I get "please add xxx.xxx.53.0/24 to this VPN tunnel, when I was sent the range .52-.55 I had a mental lapse and over thought it.

Thanks again both of you!

[pwwiddicombe]

It's the first time in a long time I've actually TRIED a subnet calculator - I do normally do it in my head - just for those that don't do it habitually, it's a good verification...   <grin>.