Uncommon IP notations

Question

I know that it is possible to write IPs in IPv4 as an integer e.g. 2130706433 instead of 127.0.0.1.

What is the reason for this possibility

Answer 1

An IPv4 address is just a 32bit number. You could represent it in any way you can represent such a number (decimal, hex, octal). The dotted notation a.b.c.d is just much more practical.

You can do the same thing with IPv6 addresses, except that those are 128bit numbers - even harder to grok in decimal form.

The usual tools will only deal with usual notations. Decimal isn't one of those.