diff --git a/tests/test_etcp_two_instances.c b/tests/test_etcp_two_instances.c
index 4ae5aa97..e7ddfcbd 100644
--- a/tests/test_etcp_two_instances.c
+++ b/tests/test_etcp_two_instances.c
@@ -163,7 +163,7 @@ static void monitor_connections(void* arg) {
                             return;
                         }
                         
-                        // Convert nat_ip to string for display
+                         // Convert nat_ip to string for display
                         char nat_ip_str[INET_ADDRSTRLEN];
                         struct in_addr nat_addr;
                         nat_addr.s_addr = htonl(link->nat_ip);
@@ -174,11 +174,26 @@ static void monitor_connections(void* arg) {
                         DEBUG_INFO(DEBUG_CATEGORY_ETCP, "[CLIENT] PASS: nat_changes_count=%u, nat_hits_count=%u",
                                    link->nat_changes_count, link->nat_hits_count);
                         
-                        // Verify it's localhost (127.0.0.1) since we're testing locally
-                        if (link->nat_ip != 0x7F000001) {  // 127.0.0.1 in host byte order
-                            DEBUG_WARN(DEBUG_CATEGORY_ETCP, "[CLIENT] WARNING: NAT IP is not 127.0.0.1 (got 0x%08X)", 
+                        // Verify NAT IP is 127.0.0.1 (localhost) since client connects from localhost
+                        // In host byte order: 127.0.0.1 = 0x7F000001
+                        if (link->nat_ip != 0x7F000001) {
+                            DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[CLIENT] FAIL: NAT IP is not 127.0.0.1 (expected 0x7F000001, got 0x%08X)", 
                                        link->nat_ip);
+                            test_completed = 2;  // Failure
+                            return;
                         }
+                        
+                        // Verify NAT port is in valid ephemeral port range (> 1024, typically)
+                        // Ephemeral ports are usually 32768-60999, but can be any > 1024
+                        if (link->nat_port <= 1024 || link->nat_port > 65535) {
+                            DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[CLIENT] FAIL: NAT port %u is out of valid range (expected > 1024 and <= 65535)", 
+                                       link->nat_port);
+                            test_completed = 2;  // Failure
+                            return;
+                        }
+                        
+                        DEBUG_INFO(DEBUG_CATEGORY_ETCP, "[CLIENT] PASS: NAT IP and port contain valid values (127.0.0.1:%u)", 
+                                   link->nat_port);
                     }
                 }
                 link = link->next;