This read-only Counter32 tallies, per its source description, the number of routes within otherwise-valid RIP packets on this interface that were ignored for any reason, such as an unknown address family or an invalid metric. Admins use a rising RcvBadRoutes count to catch a neighbor advertising malformed individual route entries even when its overall packets are well-formed, which basic packet-level counters like RcvBadPackets wouldn't reveal. For example, a neighbor advertising a route with a metric outside the valid 0-15 hop range would have that specific route rejected and counted here, even though the rest of its update is processed normally.