Merge Subnet Ranges

[onderson]

What i want to achieve with this library is something mentioned here?

https://github.com/flowchartsman/cidr-convert

Is is possible? I have seen examples on SO. but nothing similar to this c equivalent.
Could you please take a look and potentially provide some examples to give an idea on how to implement?

Cheers

[onderson]

I came up with something like this;

IPAddressString ipAddressString = new IPAddressString("10.0.80.80/31");
IPAddressString ipAddressString2 = new IPAddressString("10.0.80.82/31");
IPAddressString ipAddressString3 = new IPAddressString("10.0.80.88/30");

IPAddress first = ipAddressString.getAddress();
IPAddress second = ipAddressString2.getAddress();
IPAddress third = ipAddressString3.getAddress();

IPAddress[] blocks = first.mergeToPrefixBlocks(second,third);

System.out.println("blocks are " + Arrays.asList(blocks));

[seancfoley]

Yes, that will do it, the output of your sample code is:

blocks are [10.0.80.80/30, 10.0.80.88/30]

Also some sample code here: https://stackoverflow.com/questions/12514752/convert-ip-array-to-smallest-cidr-subnet-list-in-java/55331360#55331360

It's similar to what you have above.

Also there is a method mergeToSequentialBlocks which is similar but doesn't merge to CIDR notation, instead merges to subnets with segments shown as ranges, which can be a shorter list in some cases.

blocks are [10.0.80.80-83, 10.0.80.88-91]

[seancfoley]

Also, there is the method IPAddress.spanWithPrefixBlocks which will list all CIDR blocks between any two addresses.

So that covers all the functionality offered in the C and go language tool that you've linked to.

Also note this code here works the same with IPv6.

If you need to validate the strings, then use toAddress instead of getAddress to generate exceptions for any invalid address strings.