The -r option of netstat displays the IP routing table. Here is a sample display produced by netstat -r run on machine tenere.
Routing tables Destination Gateway Flags Refcnt Use Interface temp8milptp elvis UGH 0 0 irmcpeb1-ptp0 elvis UGH 0 0 route93-ptp0 speed UGH 0 0 mtvb9-ptp0 speed UGH 0 0 . mtnside speed UG 1 567 ray-net speed UG 0 0 mtnside-eng speed UG 0 36 mtnside-eng speed UG 0 558 mtnside-eng tenere U 33 190248 le0
The first column shows the destination network, the second the router through which packets are forwarded. The U flag indicates that the route is up; the G flag indicates that the route is to a gateway. The H flag indicates that the destination is a fully qualified host address, rather than a network.
The Refcnt column shows the number of active uses per route, and the Use column shows the number of packets sent per route. Finally, the Interface column shows the network interface that the route uses.