how to find subnet for a list of ip address

Deepika54
Tera Contributor

‎11-18-2022 05:13 AM

hello experts,

I have a a list of ip address for example from 172.102.60.70 to 172.102.60.95. we have to do a location based discovery.

Can any1 tell me how to find the subnet for these list of IP's or what is the procedure to do that.

 

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Richard Hine
Tera Guru
Tera Guru

‎11-18-2022 06:13 AM

Deepika,

 

The subnet for that address range is likely 172.102.60.64/27.

One of the easiest ways to work it out is 95-70 = 25 usable addresses which means you are looking at a subnet with over 14 addresses (/28) but with less than or equal to 30 usable addresses (/27)

 

From there you can identify the starting address of your networks:-

172.102.60.0

172.102.60.32

172.102.60.64 and so on

 

In this case, 172.102.60.64 would be the network address, 172.102.60.95 as the last address in the subnet would be the broadcast leaving 172.102.60.65-172.102.60.94 as the usable address range.

 

Hope this helps,

 

Richard

Richard Hine
Tera Guru
Tera Guru

‎11-18-2022 06:35 AM

Deepika,

 

I had posted a reply but it isn't showing up. Easiest way is to work out how many usable addresses you have, in your case you are looking for 95-70 = 25. A /28 subnet only has 14 usable addresses, a /27 subnet has 30 usable addresses, so you know you are looking at a /27.

 

In a subnet, the first address is always the network address and the last address is the broadcast address. So in your case with a /27 you are looking at these networks...

 

172.102.60.0

172.102.60.32

172.102.60.64

etc...

 

So in this case you are looking at 172.102.60.64/27 where the network address is 172.102.60.64, the broadcast would be 172.102.60.95 with the usable addresses being 172.102.60.65-94.

 

Hope this helps,

 

Richard