This counts packets received for the test instance that are not IP at all, such as raw Ethernet or Layer 2 test frames, distinguishing them from the IPv4/IPv6 counters used for IP-layer test streams. An admin checks this when the test instance was configured to send Layer 2 (non-routed) benchmark traffic, since a nonzero value here confirms the DUT is passing that traffic class through rather than dropping frames it can't classify as IP. For example, a pure Layer 2 EVC acceptance test would expect cienaCesBenchmarkTestInstanceStatsRxNonIpPkts to closely track the transmitted count while the IPv4/IPv6 counters stay at zero.