diff --git a/unittest/vslib/TestSwitchStateBase.cpp b/unittest/vslib/TestSwitchStateBase.cpp
index 85676f0a3b..31a17cfe49 100644
--- a/unittest/vslib/TestSwitchStateBase.cpp
+++ b/unittest/vslib/TestSwitchStateBase.cpp
@@ -324,6 +324,24 @@ TEST_F(SwitchStateBaseTest, switchQoSMaxNumOfTrafficClasses)
     ASSERT_EQ(attr.value.u8, maxTcNum);
 }
 
+TEST_F(SwitchStateBaseTest, switchFabricPortDefaults)
+{
+    ASSERT_EQ(m_ss->set_switch_default_attributes(), SAI_STATUS_SUCCESS);
+
+    // A switch without a fabric lane map must report 0 fabric ports rather than
+    // SAI_STATUS_NOT_IMPLEMENTED, matching hardware on a fabric-less box.
+    sai_attribute_t attr;
+    attr.id = SAI_SWITCH_ATTR_NUMBER_OF_FABRIC_PORTS;
+    ASSERT_EQ(m_ss->get(SAI_OBJECT_TYPE_SWITCH, sai_serialize_object_id(m_swid), 1, &attr), SAI_STATUS_SUCCESS);
+    ASSERT_EQ(attr.value.u32, 0U);
+
+    attr.id = SAI_SWITCH_ATTR_FABRIC_PORT_LIST;
+    attr.value.objlist.count = 0;
+    attr.value.objlist.list = nullptr;
+    ASSERT_EQ(m_ss->get(SAI_OBJECT_TYPE_SWITCH, sai_serialize_object_id(m_swid), 1, &attr), SAI_STATUS_SUCCESS);
+    ASSERT_EQ(attr.value.objlist.count, 0U);
+}
+
 TEST_F(SwitchStateBaseTest, processFipsPostConfig)
 {
     std::ofstream post_config_file(VS_SAI_FIPS_POST_CONFIG_FILE);
diff --git a/vslib/SwitchStateBase.cpp b/vslib/SwitchStateBase.cpp
index ce14568642..d2e9198423 100644
--- a/vslib/SwitchStateBase.cpp
+++ b/vslib/SwitchStateBase.cpp
@@ -1196,6 +1196,20 @@ sai_status_t SwitchStateBase::set_switch_default_attributes()
 
     CHECK_STATUS(set(SAI_OBJECT_TYPE_SWITCH, m_switch_id, &attr));
 
+    // Default to no fabric ports so a GET returns 0 rather than
+    // SAI_STATUS_NOT_IMPLEMENTED. Switches with a fabric lane map overwrite
+    // these in set_fabric_port_list().
+    attr.id = SAI_SWITCH_ATTR_NUMBER_OF_FABRIC_PORTS;
+    attr.value.u32 = 0;
+
+    CHECK_STATUS(set(SAI_OBJECT_TYPE_SWITCH, m_switch_id, &attr));
+
+    attr.id = SAI_SWITCH_ATTR_FABRIC_PORT_LIST;
+    attr.value.objlist.count = 0;
+    attr.value.objlist.list = nullptr;
+
+    CHECK_STATUS(set(SAI_OBJECT_TYPE_SWITCH, m_switch_id, &attr));
+
     return set_switch_supported_object_types();
 }