Increasing number of distribution sources has many benefits: system reliability, energy quality in some cases, voltage stability, power security, etc. Adding advantages include potential disadvantages and risks for the network and its users, in this case consumers and other electricity sources. The disadvantages may be, but are not limited to increased levels of short circuit currents, deliberate disconnection from the distribution network, poor energy quality in some cases, and risk of islanding. Islanding protection has become one of the main requirements when a new distribution source needs to be installed in the network, which requires islanding protection as one of the standard distribution source protections. Many researchers have suggested some solutions to the problem of islanding and, based on previous research, four main parts have been formed: communication-based protection, passive, active, and hybrid methods of protection. This paper reviews current applicable methods in industry and the real sector.