Wikipedia:IP hopper

An IP hopper is an unregistered or anonymous editor whose IP address changes. Mostly this would be completely outside the user's control. Some ISPs automatically assign their users a different IP address with every edit. Others may change IP address every few minutes, every few hours, every few days, or less frequently. A small number of users will keep a static IP address for many years. Users may additionally use different networks at home, at work, etc.

IP users and registered users are considered equal in status and discrimination is frowned upon when it comes to conduct and online behavior. This is wikiquette for ensuring healthy project contributions.

Some users change their IP address deliberately by resetting or changing their Internet connection. Often this might be to avoid stalking, but in a small number of cases it is done to avoid blocks or to make abusive edits without cross-check.

IPv6 addresses are expected to change frequently, though a small number may remain relatively static. Typically a user will be assigned a block of addresses for a period of time; contributions may be seen by looking at contributions from the range. In many cases this can be done by appending  to the address.

Prior experience and single purpose IPs (SPAs)
Since users can and do frequently switch from one IP address to another, it stands to reason that a user on an IP address with very few edits may have extensive prior experience editing Wikipedia, and on a variety of topics, using various other addresses.

Communicating with an IP hopper
Someone who changes IP address frequently is unlikely to see any messages left on their talk page, which can sometimes make collaboration difficult (see also WP:THEYCANTHEARYOU). If the user is editing a small number of articles the easiest way to communicate is on the article talk page. Alternatively, a registered user might try to invite the IP hopper to their own talk page in order to provide a single place for discussion. Edit summaries can sometimes work as a method of communication, but they may be better used to point to a talk page discussion.

Range hopping
Whilst it is quite common for an IP address to hop within a given range allocated to the user's ISP for example, from 1.2.3.34 to 1.2.3.87 it is less common for an editor to switch to an entirely different range, for example from 1.2.3.34 to 98.76.54.32. Such "range hopping" can be caused by an editor switching from a home WiFi connection to a mobile network, by an editor travelling, an editor changing their ISP, or by proxying. If an editor is rapidly changing between addresses that geolocate to widely different locations, this may indicate that they are proxying. If an abusive IP is range hopping, it makes rangeblocks ineffective. Some editors may only consider "true" IP hopping to be range hopping that would (or does) render rangeblocks entirely ineffective, such as editing as 1.2.3.32 at 12:00, as 98.76.54.32 at 12:02, and as 56.78.34.21 at 12:04. This means that other methods of abuse prevention must be used to deal with such editors, such as page protection.