diff --git a/tests/forwarding/BUILD.bazel b/tests/forwarding/BUILD.bazel
index 2df932c7..6431e3be 100644
--- a/tests/forwarding/BUILD.bazel
+++ b/tests/forwarding/BUILD.bazel
@@ -81,7 +81,7 @@ cc_library(
     testonly = True,
     srcs = ["smoke_test.cc"],
     hdrs = ["smoke_test.h"],
-    visibility = ["//platforms/networking/gpins/testing/blackbox/p4:__pkg__"],
+    visibility = ["//visibility:public"],
     deps = [
         ":p4_blackbox_fixture",
         ":test_data",
@@ -93,7 +93,7 @@ cc_library(
         "//sai_p4/instantiations/google:sai_p4info_cc",
         "//sai_p4/instantiations/google:sai_pd_cc_proto",
         "//thinkit:mirror_testbed_fixture",
-        "@com_google_googletest//:gtest_main",
+        "@com_google_googletest//:gtest",
     ],
     alwayslink = True,
 )
diff --git a/tests/gnoi/BUILD.bazel b/tests/gnoi/BUILD.bazel
index cba106dd..dbbdb955 100644
--- a/tests/gnoi/BUILD.bazel
+++ b/tests/gnoi/BUILD.bazel
@@ -28,11 +28,13 @@ cc_library(
     ],
     deps = [
         "//gutil:status_matchers",
+        "//gutil:testing",
         "//thinkit:mirror_testbed_fixture",
         "@com_github_gnoi//diag:diag_cc_proto",
         "@com_github_google_glog//:glog",
         "@com_github_grpc_grpc//:grpc++",
         "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/time",
         "@com_google_googletest//:gtest",
         "@com_google_protobuf//:protobuf",
     ],
diff --git a/tests/gnoi/bert_tests.cc b/tests/gnoi/bert_tests.cc
index 24450696..10411f67 100644
--- a/tests/gnoi/bert_tests.cc
+++ b/tests/gnoi/bert_tests.cc
@@ -14,54 +14,118 @@
 
 #include "tests/gnoi/bert_tests.h"
 
+#include "absl/strings/str_cat.h"
 #include "absl/strings/substitute.h"
+#include "absl/time/clock.h"
+#include "absl/time/time.h"
 #include "diag/diag.pb.h"
 #include "glog/logging.h"
 #include "google/protobuf/text_format.h"
 #include "gtest/gtest.h"
 #include "gutil/status_matchers.h"
+#include "gutil/testing.h"
 
 namespace bert {
 
-// Test StartBERT with test duration longer than maximum allowed duration.
-TEST_P(BertTest, StartBertFailsIfTestDurationTooLong) {
+using ::testing::HasSubstr;
+
+// Test StartBERT with invalid request parameters.
+TEST_P(BertTest, StartBertFailsIfRequestParametersInvalid) {
   thinkit::Switch& sut = GetMirrorTestbed().Sut();
   ASSERT_OK_AND_ASSIGN(auto sut_gnoi_diag_stub, sut.CreateGnoiDiagStub());
 
-  // Set BERT test duration to more than 24 hours: (24 hours + 1 sec).
-  constexpr uint32_t kTesDurationInSecs = (60 * 60 * 24) + 1;
+  // TODO (b/182417612) : Select one admin state "up" port.
+  gnoi::diag::StartBERTRequest valid_request =
+      gutil::ParseProtoOrDie<gnoi::diag::StartBERTRequest>(R"PROTO(
+        bert_operation_id: "OpId-1"
+        per_port_requests {
+          interface {
+            origin: "openconfig"
+            elem { name: "interfaces" }
+            elem {
+              name: "interface"
+              key { key: "name" value: "Ethernet0" }
+            }
+          }
+          prbs_polynomial: PRBS_POLYNOMIAL_PRBS23
+          test_duration_in_secs: 600
+        }
+      )PROTO");
+  // Set a unique BERT operation id using current time.
+  valid_request.set_bert_operation_id(
+      absl::StrCat("OpId-", absl::ToUnixMillis(absl::Now())));
+  gnoi::diag::StartBERTResponse response;
 
-  // TODO (ashishksingh) : Before using the "Ethernet0", run sanity test to
-  // ensure the ports are oper-state "up" on the SUT switch.
-  const std::string kStartBertRequest =
-      absl::Substitute(R"PROTO(
-                         bert_operation_id: "OpId-1"
-                         per_port_requests {
-                           interface {
-                             origin: "openconfig"
-                             elem {
-                               name: "interface"
-                               key { key: "name" value: "Ethernet0" }
-                             }
-                           }
-                           prbs_polynomial: PRBS_POLYNOMIAL_PRBS23
-                           test_duration_in_secs: $0
-                         }
-                       )PROTO",
-                       kTesDurationInSecs);
+  // Case 1: BERT test duration is 0 secs.
+  {
+    gnoi::diag::StartBERTRequest too_short_time_request = valid_request;
+    too_short_time_request.mutable_per_port_requests(0)
+        ->set_test_duration_in_secs(0);
+    grpc::ClientContext context;
+    LOG(INFO) << "Sending StartBERT request: "
+              << too_short_time_request.ShortDebugString();
+    EXPECT_THAT(gutil::GrpcStatusToAbslStatus(sut_gnoi_diag_stub->StartBERT(
+                    &context, too_short_time_request, &response)),
+                gutil::StatusIs(absl::StatusCode::kInvalidArgument,
+                                HasSubstr("is too short")));
+  }
 
-  gnoi::diag::StartBERTRequest request;
-  ASSERT_TRUE(google::protobuf::TextFormat::ParseFromString(kStartBertRequest,
-                                                            &request));
+  // Case 2: BERT test duration is more than 24 hours: (24 hours + 1 sec).
+  {
+    gnoi::diag::StartBERTRequest too_long_time_request = valid_request;
+    too_long_time_request.mutable_per_port_requests(0)
+        ->set_test_duration_in_secs(
+            ToInt64Seconds(absl::Hours(24) + absl::Seconds(1)));
+    response.Clear();
+    grpc::ClientContext context;
+    LOG(INFO) << "Sending StartBERT request: "
+              << too_long_time_request.ShortDebugString();
+    EXPECT_THAT(gutil::GrpcStatusToAbslStatus(sut_gnoi_diag_stub->StartBERT(
+                    &context, too_long_time_request, &response)),
+                gutil::StatusIs(absl::StatusCode::kInvalidArgument,
+                                HasSubstr("is too long")));
+  }
 
-  gnoi::diag::StartBERTResponse response;
-  grpc::ClientContext context;
-  LOG(INFO) << "Sending StartBERT request: " << request.ShortDebugString();
+  // Case 3: Invalid PRBS polynomial order.
+  {
+    gnoi::diag::StartBERTRequest unset_prbs_polynomial_request = valid_request;
+    unset_prbs_polynomial_request.mutable_per_port_requests(0)
+        ->clear_prbs_polynomial();
+    response.Clear();
+    grpc::ClientContext context;
+    LOG(INFO) << "Sending StartBERT request: "
+              << unset_prbs_polynomial_request.ShortDebugString();
+    EXPECT_THAT(gutil::GrpcStatusToAbslStatus(sut_gnoi_diag_stub->StartBERT(
+                    &context, unset_prbs_polynomial_request, &response)),
+                gutil::StatusIs(absl::StatusCode::kInvalidArgument,
+                                HasSubstr("PRBS polynomial is not set")));
+  }
 
-  EXPECT_THAT(gutil::GrpcStatusToAbslStatus(
-                  sut_gnoi_diag_stub->StartBERT(&context, request, &response)),
-              gutil::StatusIs(absl::StatusCode::kInvalidArgument,
-                              testing::HasSubstr("too long")));
+  // Case 4: Invalid interface.
+  {
+    gnoi::diag::StartBERTRequest invalid_interface_request = valid_request;
+    gnoi::types::Path invalid_interface =
+        gutil::ParseProtoOrDie<gnoi::types::Path>(
+            R"PROTO(
+              origin: "openconfig"
+              elem { name: "interfaces" }
+              elem {
+                name: "interface"
+                key { key: "name" value: "InvalidPort" }
+              }
+            )PROTO");
+    invalid_interface_request.mutable_per_port_requests(0)
+        ->mutable_interface()
+        ->CopyFrom(invalid_interface);
+    response.Clear();
+    grpc::ClientContext context;
+    LOG(INFO) << "Sending StartBERT request: "
+              << invalid_interface_request.ShortDebugString();
+    EXPECT_THAT(gutil::GrpcStatusToAbslStatus(sut_gnoi_diag_stub->StartBERT(
+                    &context, invalid_interface_request, &response)),
+                gutil::StatusIs(absl::StatusCode::kInvalidArgument,
+                                HasSubstr("Interface is invalid")));
+  }
 }
 
 }  // namespace bert