diff --git a/src/routing_layer/nat_detection.c b/src/routing_layer/nat_detection.c
index b231a2a0..d0de3ad2 100644
--- a/src/routing_layer/nat_detection.c
+++ b/src/routing_layer/nat_detection.c
@@ -600,6 +600,13 @@ static void select_profile(struct nat_socket *state) {
         (selected_address.ss_family && !route_ping_addr_equal(&selected_address, &state->socket->nat_addr, 1));
     if (selected.mapping == current->mapping && selected.inbound == current->inbound &&
         selected.source == current->source && !address_changed) return;
+    if (selected.source == ADDRESS_SOURCE_STUN)
+        DEBUG_INFO(DEBUG_CATEGORY_NAT, "NAT tentative EIM? socket=%s STUN_local=%s netif=%u evidence=%016llx"
+                   " mapping=%s filtering=%s age_tb=%llu working_address=%s",
+                   state->socket->name, sockaddr_storage_to_str(&stun.local).str, stun.key.netif_index,
+                   (unsigned long long)stun.evidence_id, stun_nat_mapping_name(stun.mapping),
+                   stun_nat_filtering_name(stun.filtering), (unsigned long long)(now - stun.measured_at_tb),
+                   sockaddr_storage_to_str(&selected_address).str);
     DEBUG_INFO(DEBUG_CATEGORY_NAT, "NAT selected socket=%s generation=%016llx source=%s previous=%s mapping=%s inbound=%s"
                " address_changed=%d reason=%s",
                state->socket->name, (unsigned long long)state->socket->generation, address_profile_source_name(selected.source),
diff --git a/tests/test_stun_nat.c b/tests/test_stun_nat.c
index 812ef74f..528533e0 100644
--- a/tests/test_stun_nat.c
+++ b/tests/test_stun_nat.c
@@ -371,10 +371,10 @@ static void wait_source(struct nat_fixture* nf, struct ETCP_SOCKET* socket, uint
     abort();
 }
 
-/* STUN другого порта не назначает профиль рабочему endpoint, даже без ETCP-наблюдателей. */
-static void test_fallback(void) {
+/* Оценка STUN относится к IP/netif, сохраняет рабочий порт и уступает измерению ETCP. */
+static void test_fallback(int rfc) {
     struct nat_fixture nf; nat_fixture_init(&nf);
-    struct fixture server = {.ua = nf.ua, .rfc = 1, .mapping = STUN_MAP_EIM,
+    struct fixture server = {.ua = nf.ua, .rfc = rfc, .mapping = STUN_MAP_EIM,
         .filtering = STUN_FILTER_EIF, .multiple_clients = 1}; fixture_init(&server);
     char config[512];
     snprintf(config, sizeof(config), "[stun]\nenabled=yes\nserver=127.0.0.1:%u\nserver=127.0.0.3:%u\n"
@@ -387,8 +387,10 @@ static void test_fallback(void) {
     uint64_t end = get_time_tb() + 3000000;
     do { test_clock_poll(nf.ua, 10000); assert(!stun_nat_get_socket_result(owner, socket, &diagnostic)); }
     while (get_time_tb() < end && diagnostic.status == STUN_NAT_PENDING);
-    assert(diagnostic.mapping == STUN_MAP_EIM && diagnostic.filtering == STUN_FILTER_EIF);
-    assert(socket->address_profile.source == ADDRESS_SOURCE_NONE && !socket->address_profile.mapping && !socket->address_profile.inbound);
+    assert(diagnostic.mapping == (rfc ? STUN_MAP_EIM : STUN_MAP_MATCH));
+    assert(diagnostic.filtering == (rfc ? STUN_FILTER_EIF : STUN_FILTER_UNKNOWN));
+    wait_source(&nf, socket, ADDRESS_SOURCE_STUN); wait_source(&nf, duplicate, ADDRESS_SOURCE_STUN);
+    assert(socket->address_profile.mapping == ADDRESS_MAP_EIM && socket->address_profile.inbound == ADDRESS_IN_UNKNOWN);
     assert(!memcmp(&socket->address_profile, &duplicate->address_profile, sizeof(socket->address_profile)));
     assert(!socket->nat_addr.ss_family && !duplicate->nat_addr.ss_family);
     struct nat_check_status status;
@@ -400,12 +402,47 @@ static void test_fallback(void) {
     assert(snapshot && !topo_node_verify(snapshot));
     for (const struct TOPO_ADDR4* address = snapshot->v4_addrs; address; address = address->next)
         assert(address->type != TOPO_ADDR_NAT); /* тестовый внешний порт не опубликован */
+    struct ETCP_SOCKET other = *socket;
+    other.netif_index++;
+    assert(stun_nat_get_socket_result(owner, &other, &diagnostic) < 0);
+    other = *socket;
+    ((struct sockaddr_in*)&other.local_addr)->sin_addr.s_addr = htonl(0x7f000009u);
+    assert(stun_nat_get_socket_result(owner, &other, &diagnostic) < 0);
+    struct ETCP_CONN peer = {.peer_node_id = 1};
+    struct ETCP_LINK link = {.conn = socket, .etcp = &peer};
+    struct sockaddr_storage observed = {0};
+    struct sockaddr_in* external = (struct sockaddr_in*)&observed;
+    external->sin_family = AF_INET; external->sin_addr.s_addr = htonl(0xcb007107u); external->sin_port = htons(45678);
+    nat_detection_observed_by_peer(owner->nat_det, &link, &observed);
+    assert(socket->address_profile.source == ADDRESS_SOURCE_STUN);
+    assert(route_ping_addr_equal(&socket->nat_addr, &observed, 1));
+    test_clock_run_for(nf.ua, 10001);
+    int found = 0;
+    for (const struct TOPO_ADDR4* address = snapshot->v4_addrs; address; address = address->next) {
+        if (address->type != TOPO_ADDR_NAT) continue;
+        assert(address->port == 45678 && !memcmp(address->addr, &external->sin_addr, 4)); found++;
+    }
+    assert(found == 1);
+    /* Противоречащий внешний IP исключает STUN-оценку, даже при том же локальном пути. */
+    external->sin_addr.s_addr = htonl(0xcb007108u);
+    nat_detection_observed_by_peer(owner->nat_det, &link, &observed);
+    assert(socket->address_profile.source == ADDRESS_SOURCE_ETCP && socket->address_profile.mapping == ADDRESS_MAP_UNKNOWN);
+    external->sin_addr.s_addr = htonl(0xcb007107u);
+    nat_detection_observed_by_peer(owner->nat_det, &link, &observed);
+    assert(socket->address_profile.source == ADDRESS_SOURCE_STUN);
+    /* Неудачный refresh не омолаживает кэш: EIM? исчезает после TTL. */
+    server.drop_primary = 1;
+    test_clock_run_for(nf.ua, STUN_NAT_TTL_TB + 30000);
+    assert(socket->address_profile.source == ADDRESS_SOURCE_ETCP && socket->address_profile.mapping == ADDRESS_MAP_UNKNOWN);
+    assert(route_ping_addr_equal(&socket->nat_addr, &observed, 1));
+    server.drop_primary = 0; stun_nat_recheck(owner);
+    wait_source(&nf, socket, ADDRESS_SOURCE_STUN);
     struct UTUN_INSTANCE* observer = nat_fixture_node(&nf, "127.0.0.5", NULL, NULL);
     nat_fixture_connect(&nf, owner, "udp", observer); nat_detection_request_check_all(owner->nat_det);
     end = get_time_tb() + 300000;
     do { test_clock_poll(nf.ua, 10000); nat_detection_get_status(owner->nat_det, socket, &status); }
     while (get_time_tb() < end && status.reason != NAT_REASON_NO_HELPER);
-    assert(status.reason == NAT_REASON_NO_HELPER && socket->address_profile.source == ADDRESS_SOURCE_NONE);
+    assert(status.reason == NAT_REASON_NO_HELPER && socket->address_profile.source == ADDRESS_SOURCE_STUN);
     struct UTUN_INSTANCE* helper = nat_fixture_node(&nf, "127.0.0.6", NULL, NULL);
     nat_fixture_connect(&nf, observer, "udp", helper); nat_detection_request_check_all(owner->nat_det);
     wait_source(&nf, socket, ADDRESS_SOURCE_ETCP); wait_source(&nf, duplicate, ADDRESS_SOURCE_ETCP);
@@ -418,7 +455,7 @@ static void test_fallback(void) {
     end = get_time_tb() + 3000000;
     do { test_clock_poll(nf.ua, 10000); assert(!stun_nat_get_socket_result(owner, socket, &next)); }
     while (get_time_tb() < end && next.status == STUN_NAT_PENDING);
-    assert(next.mapping == STUN_MAP_EIM && next.evidence_id != prior.evidence_id);
+    assert(next.mapping == (rfc ? STUN_MAP_EIM : STUN_MAP_MATCH) && next.evidence_id != prior.evidence_id);
     assert(!memcmp(&socket->address_profile, &measured, sizeof(measured)));
     nat_detection_request_check_all(owner->nat_det); end = get_time_tb() + 300000;
     do { test_clock_poll(nf.ua, 10000); assert(!nat_detection_get_status(owner->nat_det, socket, &status)); }
@@ -433,7 +470,7 @@ static void test_fallback(void) {
         assert(!uasync_remove_socket_t(nf.ua, server.endpoints[i].fd)); socket_close_wrapper(server.endpoints[i].fd);
     }
     socket_close_wrapper(server.source.fd); nat_fixture_cleanup(&nf);
-    DEBUG_INFO(DEBUG_CATEGORY_NAT, "PASS STUN isolation: diagnostics never replace the measured working endpoint");
+    DEBUG_INFO(DEBUG_CATEGORY_NAT, "PASS STUN EIM? RFC5780=%d: IP/netif, observed port, expiry and native priority", rfc);
 }
 
 int main(void) {
@@ -512,7 +549,7 @@ int main(void) {
     result = wait_result(&changed);
     assert(result.mapping == STUN_MAP_MATCH);
     fixture_destroy(&changed);
-    test_fallback();
+    test_fallback(0); test_fallback(1);
     test_clock_finish();
     puts("PASS STUN independent sockets, RFC5780, fallback, lifecycle and ETCP isolation");
     return 0;