Re: What data type should I use and what storage engine?

[Rick James]

Storage engine -- depends on a lot of things you have not mentioned.

For IPv4...

IP INT UNSIGNED NOT NULL
INDEX(IP)  -- or UNIQUE or PRIMARY KEY
INET_ATON()
INET_NTOA()

If you prefer, then VARBINARY(15) is suitable. Do not split it into pieces, there is no advantage. I say BINARY, not CHAR because you don't need any fancy collation. You would be using only "=", not ranges, etc.

If you need things like 111.222.111.222/28, you could store the 28 in a separate column as either a TINYINT or as a mask (again with INT UNSIGNED).

IPv6...
A guess: VARBINARY(63)