def METHOD_NAME(request):
    """OSPF verify E-bit and N-bit mismatch."""
    tc_name = request.node.name
    write_test_header(tc_name)
    tgen = get_topogen()
    # Don't run this test if we have any failure.
    if tgen.routers_have_failure():
        pytest.skip(tgen.errors)
    global topo
    step("Bring up the base config as per the topology")
    reset_config_on_routers(tgen)
    input_dict = {"r3": {"ospf6": {"neighbors": []}}}
    step("Configure r3 as stub router")
    stub = {"r3": {"ospf6": {"area": [{"id": "1.1.1.1", "type": "stub"}]}}}
    result = create_router_ospf(tgen, topo, stub)
    assert result is True, "Testcase {}: Failed \n Error: {}".format(tc_name, result)
    # Verify r3 lost its adjacency with r2 due to E-bit mismatch
    result = verify_ospf6_neighbor(tgen, topo, dut="r3", input_dict=input_dict)
    assert result is True, "Testcase {}: Failed \n Error: {}".format(tc_name, result)
    step("Configure r2 as stub router")
    stub = {"r2": {"ospf6": {"area": [{"id": "1.1.1.1", "type": "stub"}]}}}
    result = create_router_ospf(tgen, topo, stub)
    assert result is True, "Testcase {}: Failed \n Error: {}".format(tc_name, result)
    # Verify r3 has an adjacency up with r2 again
    result = verify_ospf6_neighbor(tgen, topo, dut="r3")
    assert result is True, "Testcase {}: Failed \n Error: {}".format(tc_name, result)
    step("Configure r3 as NSSA router")
    nssa = {"r3": {"ospf6": {"area": [{"id": "1.1.1.1", "type": "nssa"}]}}}
    result = create_router_ospf(tgen, topo, nssa)
    # Verify r3 lost its adjacency with r2 due to N-bit mismatch
    result = verify_ospf6_neighbor(tgen, topo, dut="r3", input_dict=input_dict)
    assert result is True, "Testcase {}: Failed \n Error: {}".format(tc_name, result)
    step("Configure r2 as NSSA router")
    nssa = {"r2": {"ospf6": {"area": [{"id": "1.1.1.1", "type": "nssa"}]}}}
    result = create_router_ospf(tgen, topo, nssa)
    # Verify r3 has an adjacency up with r2 again
    result = verify_ospf6_neighbor(tgen, topo, dut="r3")
    assert result is True, "Testcase {}: Failed \n Error: {}".format(tc_name, result)
    write_test_footer(tc_name)