- GRE is defined as an abbreviation for the Graduate Record Examination, an exam for entrance into graduate school.
The standard test taken with verbal and quantitative sections is an example of the GRE.
GRE definition by Webster's New World
gre - Computer Definition
A tunneling protocol designed by Cisco to allow the encapsulation of a wide variety of packet types in Internet Protocol (IP) packets, thereby creating a virtual pointto-point link. GRE is described in IETF RFC 1701, 1702, and 2784. See also encapsulate, IETF, IP, link, packet, point-to-point, protocol, and tunneling.
(Generic Routing Encapsulation) A tunneling protocol developed by Cisco that allows network layer packets to contain packets from a different protocol. It is widely used to tunnel protocols inside IP packets for virtual private networks (VPNs). For example, the point-to-point tunneling protocol (PPTP) is based on GRE, and GRE is used with IPsec to transmit routing protocol data from one router to another, which IPsec does not natively support. See tunneling protocol, PPTP and IPsec.