diff --git a/tests/test_etcp_two_instances.c b/tests/test_etcp_two_instances.c
new file mode 100644
index 00000000..eda18abb
--- /dev/null
+++ b/tests/test_etcp_two_instances.c
@@ -0,0 +1,178 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "../src/etcp.h"
+#include "../src/etcp_connections.h"
+#include "../src/config_parser.h"
+#include "../src/utun_instance.h"
+#include "../src/routing.h"
+#include "../src/tun_if.h"
+#include "../src/secure_channel.h"
+#include "../lib/u_async.h"
+
+#define TEST_TIMEOUT_MS 5000
+
+static struct UTUN_INSTANCE* server_instance = NULL;
+static struct UTUN_INSTANCE* client_instance = NULL;
+static int test_completed = 0;
+
+// For debug: enable in etcp_connections.c
+extern void etcp_connections_read_callback(int fd, void* arg);
+extern int etcp_encrypt_send(struct ETCP_DGRAM* dgram);
+
+static void monitor_connections(void* arg) {
+    (void)arg;
+    
+    if (test_completed) return;
+    
+    int server_links = 0;
+    int client_links = 0;
+    int client_initialized = 0;
+    
+    // Check server
+    if (server_instance) {
+        struct ETCP_CONN* conn = server_instance->connections;
+        while (conn) {
+            struct ETCP_LINK* link = conn->links;
+            while (link) {
+                server_links++;
+                printf("[SERVER] Link: peer=%llx initialized=%d type=%s\n", 
+                       (unsigned long long)conn->peer_node_id,
+                       link->initialized,
+                       link->is_server ? "server" : "client");
+                link = link->next;
+            }
+            conn = conn->next;
+        }
+    }
+    
+    // Check client
+    if (client_instance) {
+        struct ETCP_CONN* conn = client_instance->connections;
+        while (conn) {
+            struct ETCP_LINK* link = conn->links;
+            while (link) {
+                client_links++;
+                if (link->is_server == 0) {  // client link
+                    printf("[CLIENT] Link: peer=%llx initialized=%d timer=%s retry=%d\n",
+                           (unsigned long long)conn->peer_node_id,
+                           link->initialized,
+                           link->init_timer ? "active" : "null",
+                           link->init_retry_count);
+                    if (link->initialized) {
+                        client_initialized = 1;
+                    }
+                }
+                link = link->next;
+            }
+            conn = conn->next;
+        }
+    }
+    
+    // Check if connection established
+    if (client_initialized) {
+        printf("\n=== SUCCESS: Client connection established! ===\n");
+        test_completed = 1;
+        return;
+    }
+    
+    printf("[MONITOR] Server links: %d, Client links: %d, Status: %s\n",
+           server_links, client_links, 
+           client_initialized ? "CONNECTED" : "connecting...");
+    
+    // Schedule next check
+    if (!test_completed) {
+        uasync_set_timeout(NULL, 1000, NULL, monitor_connections); // Check every 1s
+    }
+}
+
+static void test_timeout(void* arg) {
+    (void)arg;
+    if (!test_completed) {
+        printf("\n=== TIMEOUT: Connection not established in %d seconds ===\n", TEST_TIMEOUT_MS/1000);
+        test_completed = 1;
+    }
+}
+
+int main() {
+    printf("=== ETCP Two-Instance Connection Test ===\n\n");
+    
+    // Create server instance
+    printf("Creating server instance...\n");
+    struct UASYNC* server_ua = uasync_create();
+    server_instance = utun_instance_create(server_ua, "test_server.conf", NULL);
+    if (!server_instance) {
+        printf("Failed to create server instance\n");
+        return 1;
+    }
+    
+    if (utun_instance_init(server_instance) < 0 ||
+        utun_instance_register_sockets(server_instance) < 0 ||
+        init_connections(server_instance) < 0) {
+        printf("Failed to initialize server instance\n");
+        utun_instance_destroy(server_instance);
+        return 1;
+    }
+    printf("Server instance ready (node_id=%llx)\n\n", (unsigned long long)server_instance->node_id);
+    
+    // Create client instance
+    printf("Creating client instance...\n");
+    struct UASYNC* client_ua = uasync_create();
+    client_instance = utun_instance_create(client_ua, "test_client.conf", NULL);
+    if (!client_instance) {
+        printf("Failed to create client instance\n");
+        utun_instance_destroy(server_instance);
+        return 1;
+    }
+    
+    if (utun_instance_init(client_instance) < 0 ||
+        utun_instance_register_sockets(client_instance) < 0 ||
+        init_connections(client_instance) < 0) {
+        printf("Failed to initialize client instance\n");
+        utun_instance_destroy(server_instance);
+        utun_instance_destroy(client_instance);
+        return 1;
+    }
+    printf("Client instance ready (node_id=%llx)\n\n", (unsigned long long)client_instance->node_id);
+    
+    // Start monitoring
+    printf("Starting connection monitoring...\n");
+    uasync_set_timeout(server_ua, 1000, NULL, monitor_connections);
+    uasync_set_timeout(server_ua, TEST_TIMEOUT_MS, NULL, test_timeout);
+    
+    // Main event loop
+    printf("Running event loop...\n\n");
+    int elapsed = 0;
+    while (!test_completed && elapsed < TEST_TIMEOUT_MS + 1000) {
+        if (server_ua) uasync_poll(server_ua, 10);
+        if (client_ua) uasync_poll(client_ua, 10);
+        
+        usleep(10000); // 10ms
+        elapsed += 10;
+    }
+    
+    // Cleanup
+    printf("\nCleaning up...\n");
+    if (server_instance) {
+        server_instance->running = 0;
+        utun_instance_destroy(server_instance);
+    }
+    if (client_instance) {
+        client_instance->running = 0;
+        utun_instance_destroy(client_instance);
+    }
+    
+    unlink("test_server.conf");
+    unlink("test_client.conf");
+    
+    if (test_completed == 1) {
+        printf("\n=== TEST PASSED ===\n");
+        return 0;
+    } else {
+        printf("\n=== TEST FAILED ===\n");
+        return 1;
+    }
+}
\ No newline at end of file
diff --git a/tests/test_etcp_two_instances_fixed.c b/tests/test_etcp_two_instances_fixed.c
new file mode 100644
index 00000000..c29bc749
--- /dev/null
+++ b/tests/test_etcp_two_instances_fixed.c
@@ -0,0 +1,108 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <time.h>
+
+#include "../src/etcp.h"
+#include "../src/etcp_connections.h"
+#include "../src/config_parser.h"
+#include "../src/utun_instance.h"
+#include "../src/routing.h"
+#include "../src/tun_if.h"
+#include "../src/secure_channel.h"
+#include "../lib/u_async.h"
+
+#define TEST_TIMEOUT_MS 5000
+
+static struct UTUN_INSTANCE* server_instance = NULL;
+static struct UTUN_INSTANCE* client_instance = NULL;
+static int test_completed = 0;
+
+static void monitor_connections(void* arg) {
+    (void)arg;
+    
+    if (test_completed) return;
+    
+    int client_initialized = 0;
+    
+    // Check client
+    if (client_instance) {
+        struct ETCP_CONN* conn = client_instance->connections;
+        while (conn) {
+            struct ETCP_LINK* link = conn->links;
+            while (link) {
+                if (link->is_server == 0) {  // client link
+                    printf("[CLIENT] Link: peer=%llx init=%d retry=%d\n",
+                           (unsigned long long)conn->peer_node_id,
+                           link->initialized,
+                           link->init_retry_count);
+                    if (link->initialized) {
+                        client_initialized = 1;
+                    }
+                }
+                link = link->next;
+            }
+            conn = conn->next;
+        }
+    }
+    
+    if (client_initialized) {
+        printf("=== SUCCESS ===\n");
+        test_completed = 1;
+        return;
+    }
+    
+    if (!test_completed) {
+        uasync_set_timeout(NULL, 1000, NULL, monitor_connections);
+    }
+}
+
+int main() {
+    printf("=== ETCP Two-Instance Test ===\n");
+    
+    // Create server config
+    FILE* f = fopen("/tmp/s.conf", "w");
+    fprintf(f, "[global]\nmy_node_id=0x1111111111111111\nmy_private_key=1313912e5d34768983b0e06530a48c77816d228a5b5605e1ab3dc443d107a3dc\nmy_public_key=dde6cec8a9023339a758f60883ef41534d24a1ffdc09bbb787a5c24ddfd891e3092461835a97d37944c681fc6b2c1f5acde8ad192f7d2cdc9920aa0d3ff78e99\ntun_ip=10.99.0.1/24\ntun_ifname=tun99\n\n[server:test]\naddr=127.0.0.1:9001\ntype=public\n");
+    fclose(f);
+    
+    // Create client config
+    f = fopen("/tmp/c.conf", "w");
+    fprintf(f, "[global]\nmy_node_id=0x2222222222222222\nmy_private_key=1313912e5d34768983b0e06530a48c77816d228a5b5605e1ab3dc443d107a3dc\nmy_public_key=dde6cec8a9023339a758f60883ef41534d24a1ffdc09bbb787a5c24ddfd891e3092461835a97d37944c681fc6b2c1f5acde8ad192f7d2cdc9920aa0d3ff78e99\ntun_ip=10.99.0.2/24\ntun_ifname=tun98\n\n[server:local]\naddr=0.0.0.0:0\ntype=nat\n\n[client:test]\npeer_node_id=0x1111111111111111\nkeepalive=1\nlink=local:127.0.0.1:9001\n");
+    fclose(f);
+    
+    struct UASYNC* sua = uasync_create();
+    struct UASYNC* cua = uasync_create();
+    
+    server_instance = utun_instance_create(sua, "/tmp/s.conf", NULL);
+    utun_instance_init(server_instance);
+    utun_instance_register_sockets(server_instance);
+    init_connections(server_instance);
+    
+    client_instance = utun_instance_create(cua, "/tmp/c.conf", NULL);
+    utun_instance_init(client_instance);
+    utun_instance_register_sockets(client_instance);
+    init_connections(client_instance);
+    
+    printf("✓ Both instances initialized\n");
+    
+    uasync_set_timeout(sua, 1000, NULL, monitor_connections);
+    
+    int elapsed = 0;
+    while (!test_completed && elapsed < TEST_TIMEOUT_MS) {
+        uasync_poll(sua, 10);
+        uasync_poll(cua, 10);
+        usleep(10000);
+        elapsed += 10;
+    }
+    
+    utun_instance_destroy(server_instance);
+    utun_instance_destroy(client_instance);
+    unlink("/tmp/s.conf");
+    unlink("/tmp/c.conf");
+    
+    return test_completed ? 0 : 1;
+}
diff --git a/tests/test_fixed b/tests/test_fixed
new file mode 100755
index 00000000..2fef2770
Binary files /dev/null and b/tests/test_fixed differ