title: Selenium proxy server argument - unknown error: net::ERR_TUNNEL_CONNECTION_FAILED
body: <p>Hope you're well.</p>
  <p>I am facing a little problem when trying to set-up my chrome webdriver. I am trying to change the parameters of the webdriver to rotate the User Agent &amp; the IP (I use it for scraping purpose &amp; don't want to get spot with the same IP &amp; UA).</p>
  <p>When I pass the UA argument, everything works well. But when I add the IP argument, it systematically fails for some reasons that I can't identify. I always receive the following error</p>
  <pre><code>WebDriverException: unknown error: net::ERR_TUNNEL_CONNECTION_FAILED
    (Session info: chrome=86.0.4240.198)```
  
  </code></pre>
  <p>The behavior is always the same, the driver opens the web page as requested, then the page loads for a while until indicating the site is not accessible.</p>
  <p>Below is the code used. Do you have any idea where it could come from? (I have not able to find similar posts on this unfortunately)</p>
  <pre><code>from selenium import webdriver
  from selenium.webdriver.chrome.options import Options
  
  
  
  opts = Options()
  user_agent = 'Mozilla/5.0 CK={} (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko'
  PROXY = '176.9.119.170:8080'
  
  opts.add_argument(&quot;user-agent=&quot;+user_agent)
  opts.add_argument(&quot;--proxy-server=%s&quot; % PROXY)
  
  driver = webdriver.Chrome(executable_path='XXXXXXXX', options=opts)
          
  
  driver.get('https://www.expressvpn.com/what-is-my-ip')
  user_agent_check = driver.execute_script(&quot;return navigator.userAgent;&quot;)
  print(user_agent_check)
  </code></pre>
  <p>Traceback below</p>
  <pre><code># Licensed to the Software Freedom Conservancy (SFC) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The SFC licenses this file
  # to you under the Apache License, Version 2.0 (the
  # &quot;License&quot;); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  
  from selenium.common.exceptions import (ElementClickInterceptedException,
                                          ElementNotInteractableException,
                                          ElementNotSelectableException,
                                          ElementNotVisibleException,
                                          ErrorInResponseException,
                                          InsecureCertificateException,
                                          InvalidCoordinatesException,
                                          InvalidElementStateException,
                                          InvalidSessionIdException,
                                          InvalidSelectorException,
                                          ImeNotAvailableException,
                                          ImeActivationFailedException,
                                          InvalidArgumentException,
                                          InvalidCookieDomainException,
                                          JavascriptException,
                                          MoveTargetOutOfBoundsException,
                                          NoSuchCookieException,
                                          NoSuchElementException,
                                          NoSuchFrameException,
                                          NoSuchWindowException,
                                          NoAlertPresentException,
                                          ScreenshotException,
                                          SessionNotCreatedException,
                                          StaleElementReferenceException,
                                          TimeoutException,
                                          UnableToSetCookieException,
                                          UnexpectedAlertPresentException,
                                          UnknownMethodException,
                                          WebDriverException)
  
  try:
      basestring
  except NameError:  # Python 3.x
      basestring = str
  
  
  class ErrorCode(object):
      &quot;&quot;&quot;
      Error codes defined in the WebDriver wire protocol.
      &quot;&quot;&quot;
      # Keep in sync with org.openqa.selenium.remote.ErrorCodes and errorcodes.h
      SUCCESS = 0
      NO_SUCH_ELEMENT = [7, 'no such element']
      NO_SUCH_FRAME = [8, 'no such frame']
      UNKNOWN_COMMAND = [9, 'unknown command']
      STALE_ELEMENT_REFERENCE = [10, 'stale element reference']
      ELEMENT_NOT_VISIBLE = [11, 'element not visible']
      INVALID_ELEMENT_STATE = [12, 'invalid element state']
      UNKNOWN_ERROR = [13, 'unknown error']
      ELEMENT_IS_NOT_SELECTABLE = [15, 'element not selectable']
      JAVASCRIPT_ERROR = [17, 'javascript error']
      XPATH_LOOKUP_ERROR = [19, 'invalid selector']
      TIMEOUT = [21, 'timeout']
      NO_SUCH_WINDOW = [23, 'no such window']
      INVALID_COOKIE_DOMAIN = [24, 'invalid cookie domain']
      UNABLE_TO_SET_COOKIE = [25, 'unable to set cookie']
      UNEXPECTED_ALERT_OPEN = [26, 'unexpected alert open']
      NO_ALERT_OPEN = [27, 'no such alert']
      SCRIPT_TIMEOUT = [28, 'script timeout']
      INVALID_ELEMENT_COORDINATES = [29, 'invalid element coordinates']
      IME_NOT_AVAILABLE = [30, 'ime not available']
      IME_ENGINE_ACTIVATION_FAILED = [31, 'ime engine activation failed']
      INVALID_SELECTOR = [32, 'invalid selector']
      SESSION_NOT_CREATED = [33, 'session not created']
      MOVE_TARGET_OUT_OF_BOUNDS = [34, 'move target out of bounds']
      INVALID_XPATH_SELECTOR = [51, 'invalid selector']
      INVALID_XPATH_SELECTOR_RETURN_TYPER = [52, 'invalid selector']
  
      ELEMENT_NOT_INTERACTABLE = [60, 'element not interactable']
      INSECURE_CERTIFICATE = ['insecure certificate']
      INVALID_ARGUMENT = [61, 'invalid argument']
      INVALID_COORDINATES = ['invalid coordinates']
      INVALID_SESSION_ID = ['invalid session id']
      NO_SUCH_COOKIE = [62, 'no such cookie']
      UNABLE_TO_CAPTURE_SCREEN = [63, 'unable to capture screen']
      ELEMENT_CLICK_INTERCEPTED = [64, 'element click intercepted']
      UNKNOWN_METHOD = ['unknown method exception']
  
      METHOD_NOT_ALLOWED = [405, 'unsupported operation']
  
  
  class ErrorHandler(object):
      &quot;&quot;&quot;
      Handles errors returned by the WebDriver server.
      &quot;&quot;&quot;
      def check_response(self, response):
          &quot;&quot;&quot;
          Checks that a JSON response from the WebDriver does not have an error.
  
          :Args:
           - response - The JSON response from the WebDriver server as a dictionary
             object.
  
          :Raises: If the response contains an error message.
          &quot;&quot;&quot;
          status = response.get('status', None)
          if status is None or status == ErrorCode.SUCCESS:
              return
          value = None
          message = response.get(&quot;message&quot;, &quot;&quot;)
          screen = response.get(&quot;screen&quot;, &quot;&quot;)
          stacktrace = None
          if isinstance(status, int):
              value_json = response.get('value', None)
              if value_json and isinstance(value_json, basestring):
                  import json
                  try:
                      value = json.loads(value_json)
                      if len(value.keys()) == 1:
                          value = value['value']
                      status = value.get('error', None)
                      if status is None:
                          status = value[&quot;status&quot;]
                          message = value[&quot;value&quot;]
                          if not isinstance(message, basestring):
                              value = message
                              message = message.get('message')
                      else:
                          message = value.get('message', None)
                  except ValueError:
                      pass
  
          exception_class = ErrorInResponseException
          if status in ErrorCode.NO_SUCH_ELEMENT:
              exception_class = NoSuchElementException
          elif status in ErrorCode.NO_SUCH_FRAME:
              exception_class = NoSuchFrameException
          elif status in ErrorCode.NO_SUCH_WINDOW:
              exception_class = NoSuchWindowException
          elif status in ErrorCode.STALE_ELEMENT_REFERENCE:
              exception_class = StaleElementReferenceException
          elif status in ErrorCode.ELEMENT_NOT_VISIBLE:
              exception_class = ElementNotVisibleException
          elif status in ErrorCode.INVALID_ELEMENT_STATE:
              exception_class = InvalidElementStateException
          elif status in ErrorCode.INVALID_SELECTOR \
                  or status in ErrorCode.INVALID_XPATH_SELECTOR \
                  or status in ErrorCode.INVALID_XPATH_SELECTOR_RETURN_TYPER:
              exception_class = InvalidSelectorException
          elif status in ErrorCode.ELEMENT_IS_NOT_SELECTABLE:
              exception_class = ElementNotSelectableException
          elif status in ErrorCode.ELEMENT_NOT_INTERACTABLE:
              exception_class = ElementNotInteractableException
          elif status in ErrorCode.INVALID_COOKIE_DOMAIN:
              exception_class = InvalidCookieDomainException
          elif status in ErrorCode.UNABLE_TO_SET_COOKIE:
              exception_class = UnableToSetCookieException
          elif status in ErrorCode.TIMEOUT:
              exception_class = TimeoutException
          elif status in ErrorCode.SCRIPT_TIMEOUT:
              exception_class = TimeoutException
          elif status in ErrorCode.UNKNOWN_ERROR:
              exception_class = WebDriverException
          elif status in ErrorCode.UNEXPECTED_ALERT_OPEN:
              exception_class = UnexpectedAlertPresentException
          elif status in ErrorCode.NO_ALERT_OPEN:
              exception_class = NoAlertPresentException
          elif status in ErrorCode.IME_NOT_AVAILABLE:
              exception_class = ImeNotAvailableException
          elif status in ErrorCode.IME_ENGINE_ACTIVATION_FAILED:
              exception_class = ImeActivationFailedException
          elif status in ErrorCode.MOVE_TARGET_OUT_OF_BOUNDS:
              exception_class = MoveTargetOutOfBoundsException
          elif status in ErrorCode.JAVASCRIPT_ERROR:
              exception_class = JavascriptException
          elif status in ErrorCode.SESSION_NOT_CREATED:
              exception_class = SessionNotCreatedException
          elif status in ErrorCode.INVALID_ARGUMENT:
              exception_class = InvalidArgumentException
          elif status in ErrorCode.NO_SUCH_COOKIE:
              exception_class = NoSuchCookieException
          elif status in ErrorCode.UNABLE_TO_CAPTURE_SCREEN:
              exception_class = ScreenshotException
          elif status in ErrorCode.ELEMENT_CLICK_INTERCEPTED:
              exception_class = ElementClickInterceptedException
          elif status in ErrorCode.INSECURE_CERTIFICATE:
              exception_class = InsecureCertificateException
          elif status in ErrorCode.INVALID_COORDINATES:
              exception_class = InvalidCoordinatesException
          elif status in ErrorCode.INVALID_SESSION_ID:
              exception_class = InvalidSessionIdException
          elif status in ErrorCode.UNKNOWN_METHOD:
              exception_class = UnknownMethodException
          else:
              exception_class = WebDriverException
          if value == '' or value is None:
              value = response['value']
          if isinstance(value, basestring):
              if exception_class == ErrorInResponseException:
                  raise exception_class(response, value)
              raise exception_class(value)
          if message == &quot;&quot; and 'message' in value:
              message = value['message']
  
          screen = None
          if 'screen' in value:
              screen = value['screen']
  
          stacktrace = None
          if 'stackTrace' in value and value['stackTrace']:
              stacktrace = []
              try:
                  for frame in value['stackTrace']:
                      line = self._value_or_default(frame, 'lineNumber', '')
                      file = self._value_or_default(frame, 'fileName', '&lt;anonymous&gt;')
                      if line:
                          file = &quot;%s:%s&quot; % (file, line)
                      meth = self._value_or_default(frame, 'methodName', '&lt;anonymous&gt;')
                      if 'className' in frame:
                          meth = &quot;%s.%s&quot; % (frame['className'], meth)
                      msg = &quot;    at %s (%s)&quot;
                      msg = msg % (meth, file)
                      stacktrace.append(msg)
              except TypeError:
                  pass
          if exception_class == ErrorInResponseException:
              raise exception_class(response, message)
          elif exception_class == UnexpectedAlertPresentException:
              alert_text = None
              if 'data' in value:
                  alert_text = value['data'].get('text')
              elif 'alert' in value:
                  alert_text = value['alert'].get('text')
              raise exception_class(message, screen, stacktrace, alert_text)
          raise exception_class(message, screen, stacktrace)
  
      def _value_or_default(self, obj, key, default):
          return obj[key] if key in obj else default
  
  
  </code></pre>
  <p>Thank you for your help</p>