Adding a route to specific host go out a specific interface

On a newer machine using the ip binary the syntax to add a route is slightly different (but thankfully really consistent for hosts/networks/etc).

ip route add 10.0.1.3 via 10.0.0.1 dev eth0

If you were going to add a new default route for a new 10.0.2.0 network through the eth1 interface it might be something like this.

ip route add 10.0.2.0/24 via 10.0.1.1 dev eth1

Source: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Deployment_Guide/s1-networkscripts-static-routes.html

# route add -host 10.0.1.3 dev eth0