Deduplicate resolved endpoints before sizing the attempt budget

esphome/espota2.py

@@ -580,6 +580,18 @@ def run_ota_impl_(
         _LOGGER.error("No addresses to connect to for %s", remote_host)
         return 1, None
 
+    # The same device often resolves through several names (mDNS name,
+    # use_address, MQTT discovery), so drop duplicate endpoints; they add no
+    # new path to the device but would inflate the attempt budget below.
+    seen_endpoints: set[tuple[int, tuple]] = set()
+    unique_res = []
+    for r in res:
+        endpoint = (r[0], r[4])
+        if endpoint not in seen_endpoints:
+            seen_endpoints.add(endpoint)
+            unique_res.append(r)
+    res = unique_res
+
     # Every address is tried at least once and EXTRA_UPLOAD_ATTEMPTS retries
     # are shared across the addresses, cycling through them. Wait before an
     # attempt when the previous one actually reached the device, or when

tests/unit_tests/test_espota2.py

@@ -851,6 +851,25 @@ def test_run_ota_impl_multiple_addresses_cycle(
     assert mock_sleep.call_count == 2
 
 
+@pytest.mark.usefixtures("mock_socket_constructor")
+def test_run_ota_impl_duplicate_addresses_deduplicated(
+    mock_socket: Mock, firmware_file: Path, mock_resolve_ip: Mock, mock_sleep: Mock
+) -> None:
+    """Test duplicate resolved endpoints do not inflate the attempt budget."""
+    entry = (socket.AF_INET, socket.SOCK_STREAM, 0, "", ("192.168.1.100", 3232))
+    mock_resolve_ip.return_value = [entry, entry]
+    mock_socket.connect.side_effect = OSError("Connection refused")
+
+    result_code, result_host = espota2.run_ota_impl_(
+        "test.local", 3232, "password", str(firmware_file)
+    )
+
+    assert result_code == 1
+    assert result_host is None
+    # The duplicate collapses to one endpoint, so the budget is 1 + EXTRA
+    assert mock_socket.connect.call_count == espota2.EXTRA_UPLOAD_ATTEMPTS + 1
+
+
 @pytest.mark.usefixtures("mock_socket_constructor", "mock_resolve_ip_dual")
 def test_run_ota_impl_second_address_succeeds_without_delay(
     mock_socket: Mock,