1. A method comprising: querying, by a routing validation machine, a router in a network to obtain a first routing table from the router, simulating a model of the network to obtain a second routing table corresponding to a model of the router, identifying, by the routing validation machine, differences, if any, between the first routing table and the second routing table, and presenting, by the routing validation machine, information based on the differences, wherein the first and second routing tables include a next hop entry and a metric entry for each of a plurality of destination prefixes, and identifying the differences includes identifying differences between the next hop entries and the metric entries of the first and second routing tables.