* IP - This is the abbreviation for Internet Protocol, a set of rules that govern how data is transmitted over the internet.
* i.p. - This is a shortened form of "in particular", often used in writing.
* ip - This could be a misspelling of "yip" (a short, sharp bark) or "hip" (referring to the joint between the thigh and the pelvis).
To understand which spelling is correct, you need to consider the surrounding text and the intended meaning.