}

    /**
     * State tracking for channel failover
     */
    public static class FailoverState {

        private final String channelId;
        private final long failureTime;
        private int retryCount;
        private long nextRetryTime;

        /**
         * Create failover state
         *
         * @param channelId channel identifier
         */

    @Mock
    private SmbTransport mockNewTransport;

    @Mock
    private CommonServerMessageBlock mockOperation;

    private ChannelFailover failover;
    private ChannelInfo failedChannel;

    @BeforeEach
    void setUp() throws UnknownHostException {
        failover = new ChannelFailover(mockChannelManager);

        InetAddress addr = InetAddress.getByName("192.168.1.100");

## 1. Overview

SMB3 Multi-Channel enables the use of multiple network connections between client and server, providing increased throughput, network fault tolerance, and automatic failover capabilities. This feature aggregates bandwidth across multiple NICs and provides seamless failover when network paths fail.

## 2. Protocol Specification Reference

- **MS-SMB2 Section 3.2.4.23**: FSCTL_QUERY_NETWORK_INTERFACE_INFO

 */
public enum WitnessEventType {
    /**
     * Resource state changed - general resource state modification
     */
    RESOURCE_CHANGE(1),

    /**
     * Client should move to different node - directed failover
     */
    CLIENT_MOVE(2),

    /**
     * Share moved to different node - share mobility event
     */
    SHARE_MOVE(3),

    /**
     * IP address changed - network configuration change
     */

    
    // Simulate cluster failover (would require test environment setup)
    // ... trigger server failover ...
    
    // Verify that witness notification was received and handled
    assertTrue(listener.waitForNotification(30000));  // 30 second timeout
    
    // Verify file is still accessible after failover
    assertTrue(file.exists());
}

@Test

Calls are executed in one of two ways:

 * **Synchronous:** your thread blocks until the response is readable.

/**
 * SMB Witness Protocol client implementation as defined in MS-SWN specification.
 * Manages witness registrations, notifications, and heartbeats for cluster failover support.
 */
public class WitnessClient implements AutoCloseable {
    private static final Logger log = LoggerFactory.getLogger(WitnessClient.class);

    // Polling and backoff constants (in ms)

    protected boolean forceExtendedSecurity = false;
    /** Whether to negotiate only SMB2 or higher protocols */
    protected boolean smb2OnlyNegotiation = false;
    /** Whether to failover to port 139 if port 445 fails */
    protected boolean port139FailoverEnabled = false;
    /** Whether to use NT SMB operations */
    protected boolean useNTSmbs = true;

                setSessionSetup(response);

                // Initialize multi-channel after successful session setup
                initializeMultiChannel();

                // Initialize witness support for fast failover
                initializeWitnessSupport();

                if (ex != null) {
                    throw ex;
                }
                return (T) (response != null ? response.getNextResponse() : null);

        poolSpy.logon(ctx, address);

        // Then: Should connect to IPC$ share
        verify(tree).connectLogon(ctx);
    }

    @Test
    @DisplayName("Should sort addresses by fail count and failover")
    void testFailoverWithFailCounts() throws Exception {
        // Given: Multiple addresses with different fail counts
        Address addr1 = mock(Address.class);