A method of detecting one or more routing policies of one or more autonomous systems or routers on a network and routing anomalies on the network, the method comprising: retrieving, by a computer system, a plurality of network routes on the network; determining, by the computer system, a route automaton (300, 500, 600) based on the plurality of network routes, wherein the route automaton is a finite-state machine that defines a finite number of states and transitions between those states, wherein the route automaton represents inter-domain network routes, and wherein determining the route automaton comprises: determining a deterministic finite-state automaton based on the plurality of network routes, wherein the deterministic finite-state automaton comprises a plurality of states and a plurality of paths between the states, wherein each state is associated with a respective routing policy of an autonomous system or a router on the network, and performing a minimization operation with respect to the deterministic finite-state automaton, wherein the minimization comprises combining two or more states associated with a similar routing policy, and reducing a number of states of the deterministic finite-state automaton such that the deterministic finite-state automaton includes a minimum number of unique states necessary to represent each of the network routes; determining, by the computer system, one or more routing policies on the network based on said route automaton; and detecting, by the computer system, routing anomalies on the network based on the one or more routing policies and said route automaton. the method comprising: retrieving, by a computer system, a plurality of network routes on the network; determining, by the computer system, a route automaton (300, 500, 600) based on the plurality of network routes, wherein the route automaton is a finite-state machine that defines a finite number of states and transitions between those states, wherein the route automaton represents inter-domain network routes, and retrieving, by a computer system, a plurality of network routes on the network; determining, by the computer system, a route automaton (300, 500, 600) based on the plurality of network routes, wherein the route automaton is a finite-state machine that defines a finite number of states and transitions between those states, wherein the route automaton represents inter-domain network routes, and wherein determining the route automaton comprises: determining a deterministic finite-state automaton based on the plurality of network routes, wherein the deterministic finite-state automaton comprises a plurality of states and a plurality of paths between the states, wherein each state is associated with a respective routing policy of an autonomous system or a router on the network, and performing a minimization operation with respect to the deterministic finite-state automaton, wherein the minimization comprises combining two or more states associated with a similar routing policy, and reducing a number of states of the deterministic finite-state automaton such that the deterministic finite-state automaton includes a minimum number of unique states necessary to represent each of the network routes; determining, by the computer system, one or more routing policies on the network based on said route automaton; and detecting, by the computer system, routing anomalies on the network based on the one or more routing policies and said route automaton. determining a deterministic finite-state automaton based on the plurality of network routes, wherein the deterministic finite-state automaton comprises a plurality of states and a plurality of paths between the states, wherein each state is associated with a respective routing policy of an autonomous system or a router on the network, and performing a minimization operation with respect to the deterministic finite-state automaton, wherein the minimization comprises combining two or more states associated with a similar routing policy, and reducing a number of states of the deterministic finite-state automaton such that the deterministic finite-state automaton includes a minimum number of unique states necessary to represent each of the network routes; determining, by the computer system, one or more routing policies on the network based on said route automaton; and detecting, by the computer system, routing anomalies on the network based on the one or more routing policies and said route automaton.