ifmetric - An IPv4 route metrics manipulation tool
ifmetric INTERFACE [METRIC]
ifmetric is a Linux tool for setting the metrics of all IPv4 routes attached to a given network interface at once. This may be used to change the priority of routing IPv4 traffic over the interface. Lower metrics correlate with higher priorities.
ifmetric uses the Linux NETLINK interface to manipulate the routes. Because of that it is compatible with routes created with the new iproute2 utility.
You should specify the interface name as first parameter. The second parameter should be the new metric. If ommited the metric 0 (highest) is used.