This value, from 0 to 15, is the metric-in adjustment applied to routes received via RIP on this interface, defaulting to 0. Admins adjust it to make routes learned on a particular interface appear more or less preferable by artificially raising their hop count as they come in. Setting gbnL3RipMetricIn to 2 on a backup link's interface makes routes learned there appear two hops farther, so the primary link's routes are preferred.