Point to point, Hub & Spoke, Mesh*Point-to-Point* - This is the simplest topology that consists of a permanent link between two endpoints. For this reason, this is a very popular WAN topology.*Hub and Spoke* - A WAN version of the star topology in which a central site interconnects branch sites using point-to-point links.*Mesh* - This topology provides high availability, but requires that every end system be interconnected to every other system. Therefore, the administrative and physical costs can be significant. Each link is essentially a point-to-point link to the other node.*