Skip RX_DRP check on Mellanox platform in test_drop_l3_ip_packet_non_…

…dut_mac (sonic-net#15248)

tests/ip/test_ip_packet.py

@@ -739,8 +739,11 @@ def test_drop_l3_ip_packet_non_dut_mac(self, duthosts, enum_rand_one_per_hwsku_f
             return
         pytest_assert(rx_ok >= self.PKT_NUM_MIN,
                       "Received {} packets in rx, not in expected range".format(rx_ok))
-        pytest_assert(rx_drp >= self.PKT_NUM_MIN,
-                      "Dropped {} packets in rx, not in expected range".format(rx_drp))
+        asic_type = duthost.facts["asic_type"]
+        # Packet is dropped silently on Mellanox platform if the destination MAC address is not the router MAC
+        if asic_type not in ["mellanox"]:
+            pytest_assert(rx_drp >= self.PKT_NUM_MIN,
+                          "Dropped {} packets in rx, not in expected range".format(rx_drp))
         pytest_assert(tx_ok <= self.PKT_NUM_ZERO,
                       "Forwarded {} packets in tx, not in expected range".format(tx_ok))
         pytest_assert(max(tx_drp, tx_rif_err) <= self.PKT_NUM_ZERO,