diff --git a/config/install/domain_301_redirect.settings.yml b/config/install/domain_301_redirect.settings.yml
index df519d6..dc5eda3 100644
--- a/config/install/domain_301_redirect.settings.yml
+++ b/config/install/domain_301_redirect.settings.yml
@@ -1,7 +1,9 @@
 enabled: 0
-check_period: 60 * 60 * 3
+check_period: 10800
 domain_check_retries: 3
 domain_check_reenable: true
 disabled_by_check: false
-enabled: 0
 last_checked: 0
+loop_max_redirects: 3
+applicability: 0
+pages: ''
diff --git a/config/schema/domain_301_redirect.schema.yml b/config/schema/domain_301_redirect.schema.yml
new file mode 100644
index 0000000..519709b
--- /dev/null
+++ b/config/schema/domain_301_redirect.schema.yml
@@ -0,0 +1,37 @@
+# Schema for the configuration files of the Domain 301 Redirect module.
+
+domain_301_redirect.settings:
+  type: config_object
+  label: 'Domain 301 redirect settings'
+  mapping:
+    enabled:
+      type: integer
+      label: 'Enable to start 301 redirects to the domain'
+    domain:
+      type: string
+      label: 'Domain'
+    check_period:
+      type: integer
+      label: 'Selects the period between domain'
+    domain_check_retries:
+      type: integer
+      label: 'Number of times to check domain availability'
+    domain_check_reenable:
+      type: boolean
+      label: 'Re-enable domain redirection'
+    disabled_by_check:
+      type: boolean
+      label: 'Disable domain redirection'
+    last_checked:
+      type: integer
+      label: 'Redirect is disabled by cron'
+    applicability:
+        type: path_settings
+        label: 'Specify pages'
+        mapping:
+            applicability:
+              type: integer
+              label: 'Redirect on specific pages'
+            pages:
+              type: string
+              label: 'Pages to include or exclude from redirection'
diff --git a/domain_301_redirect.links.menu.yml b/domain_301_redirect.links.menu.yml
new file mode 100644
index 0000000..ae8972d
--- /dev/null
+++ b/domain_301_redirect.links.menu.yml
@@ -0,0 +1,5 @@
+domain_301_redirect.settings:
+  title: 'Domain 301 Redirect'
+  parent: system.admin_config_search
+  description: 'Configure Domain 301 Redirect.'
+  route_name: domain_301_redirect.settings
diff --git a/domain_301_redirect.module b/domain_301_redirect.module
index f614170..2da98ad 100644
--- a/domain_301_redirect.module
+++ b/domain_301_redirect.module
@@ -17,3 +17,42 @@ function domain_301_redirect_help($route_name, RouteMatchInterface $route_match)
       return ['#markup' => $output];
   }
 }
+
+/**
+ * Implements hook_cron().
+ */
+function domain_301_redirect_cron() {
+  $config = $config = \Drupal::config('domain_301_redirect.settings');
+  $enabled = $config->get('enabled');
+  $check_period = $config->get('check_period');
+  $last_checked = $config->get('last_checked');
+  $reenable = $config->get('check_reenable');
+  $disabled_by_check = $config->get('disabled_by_check');
+
+  // If the redirect is enabled (or has been previously disabled) and we are
+  // checking for domain availability on cron, then attempt to request the test
+  // url using the redirect domain.
+  if (($enabled || ($disabled_by_check && $reenable)) && !empty($check_period) && $last_checked < time() - $check_period) {
+   $domain = variable_get('domain_301_redirect_domain', '');
+   if (!preg_match('|^https?://|', $domain)) {
+     $domain = 'http://' . $domain;
+   }
+   $domain_parts = parse_url($domain);
+   $domain = $domain_parts['scheme'] . '://' . $domain_parts['host'];
+   if (!domain_301_redirect_check_domain($domain)) {
+     variable_set('domain_301_redirect_enabled', 0);
+     variable_set('domain_301_redirect_disabled_by_check', TRUE);
+     watchdog('Domain 301 Redirect', 'The domain %domain no longer points to this site. Domain 301 redirection was disabled.', array('%domain' => $domain), WATCHDOG_ERROR);
+   }
+   else {
+     watchdog('Domain 301 Redirect', 'Domain 301 redirect check passed.');
+     // If the redirect was disabled by cron, and it has now passed, re-enable it.
+     if (!$enabled && $reenable && $disabled_by_check) {
+       variable_set('domain_301_redirect_enabled', 1);
+       variable_set('domain_301_redirect_disabled_by_check', FALSE);
+       watchdog('Domain 301 Redirect', 'The domain %domain has become available again. Domain 301 redirection was re-enabled.', array('%domain' => $domain), WATCHDOG_ERROR);
+     }
+   }
+   variable_set('domain_301_redirect_last_checked', time());
+  }
+}
diff --git a/domain_301_redirect.permissions.yml b/domain_301_redirect.permissions.yml
new file mode 100644
index 0000000..59ed00a
--- /dev/null
+++ b/domain_301_redirect.permissions.yml
@@ -0,0 +1,4 @@
+bypass domain 301 redirect:
+  title: 'Bypass domain 301 redirect'
+  description: 'If this permission is set, the user will not be 301 redirected if the domain does not match the main domain.'
+  restrict access: true
diff --git a/domain_301_redirect.services.yml b/domain_301_redirect.services.yml
new file mode 100644
index 0000000..d9c6d61
--- /dev/null
+++ b/domain_301_redirect.services.yml
@@ -0,0 +1,11 @@
+services:
+  domain_301_redirect.event_subscriber:
+    class: Drupal\domain_301_redirect\EventSubscriber\DomainRedirectEventSubscriber
+    arguments: ['@config.factory', '@request_stack', '@current_user']
+    tags:
+      - { name: event_subscriber }
+
+  domain_301_redirect.manager:
+    class: Drupal\domain_301_redirect\Domain301RedirectManager
+    tags:
+      - {name: domain_301_redirect_manager}
diff --git a/src/Domain301RedirectManager.php b/src/Domain301RedirectManager.php
new file mode 100644
index 0000000..3351e53
--- /dev/null
+++ b/src/Domain301RedirectManager.php
@@ -0,0 +1,82 @@
+<?php
+
+namespace Drupal\domain_301_redirect;
+
+use Drupal\Component\Utility\Unicode;
+
+/**
+ * Defines an Domain301RedirectManager service.
+ */
+class Domain301RedirectManager implements Domain301RedirectManagerInterface {
+
+  /**
+   * A config object for the Default Content Extra configuration.
+   *
+   * @var \Drupal\Core\Config\Config
+   */
+  protected $config;
+
+  /**
+   * Constructs an Domain301RedirectManager object.
+   *
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The Configuration Factory.
+   */
+  public function __construct(ConfigFactoryInterface $config_factory) {
+    $this->config = $config_factory->get('domain_301_redirect.settings');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function checkRedirectLoop($domain) {
+    // Get host from configured domain.
+    $redirect_host = Unicode::strtolower(parse_url($domain, PHP_URL_HOST));
+    $host = Unicode::strtolower(parse_url($GLOBALS['base_url'], PHP_URL_HOST));
+
+    // Redirecting back to this site actually is actively ignored in hook_init,
+    // so it makes no sense to allow users to set this as a value. On the other
+    // hand when the admin is on the redirected domain he should still be able
+    // to alter other settings without first disabling redirection. So let's
+    // just accept the current host.
+    if ($redirect_host == $host) {
+      return FALSE;
+    }
+
+    $redirect_loop = FALSE;
+    $redirects_to_check = $this->config->get('loop_max_redirects');
+    $checked = 0;
+
+    // Make a request to the domain that is being configured, following a
+    // configured number of redirects. This has to be done individually, because
+    // if checking all 3 levels at once, we might happen to get the wrong one
+    // back (if the redirect loop has multiple levels).
+    do {
+      $client = \Drupal::httpClient();
+      $args = [
+        'max_redirects' => 0,
+        'method' => 'HEAD',
+        'headers' => [
+          'Accept' => 'text/plain',
+        ],
+      ];
+      $response = $client->get($domain, $args);
+
+      if (!empty($response->redirect_url)) {
+        // Request target for the next request loop.
+        $domain = $response->redirect_url;
+        // Check if any host names match the redirect host name.
+        $location_host = Unicode::strtolower(parse_url($response->redirect_url, PHP_URL_HOST));
+        if ($redirect_host == $location_host || $host == $location_host) {
+          $redirect_loop = TRUE;
+        }
+      }
+      $checked++;
+      // Don't check the redirect code, as it's possible there may be another
+      // redirect service in operation that does not use 301.
+    } while (!$redirect_loop && !empty($response->redirect_url) && $checked < $redirects_to_check);
+
+    return $redirect_loop;
+  }
+
+}
diff --git a/src/Domain301RedirectManagerInterface.php b/src/Domain301RedirectManagerInterface.php
new file mode 100644
index 0000000..7be044e
--- /dev/null
+++ b/src/Domain301RedirectManagerInterface.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Drupal\domain_301_redirect;
+
+/**
+ * Interface for Domain301RedirectManager.
+ */
+interface Domain301RedirectManagerInterface {
+
+  /**
+   * Determine if connection should be refreshed.
+   *
+   * @return array
+   *   Returns the list of options that domain_301_redirect provides.
+   */
+  public function checkRedirectLoop($domain);
+
+}
diff --git a/src/EventSubscriber/DomainRedirectEventSubscriber.php b/src/EventSubscriber/DomainRedirectEventSubscriber.php
new file mode 100644
index 0000000..1e73fef
--- /dev/null
+++ b/src/EventSubscriber/DomainRedirectEventSubscriber.php
@@ -0,0 +1,106 @@
+<?php
+
+namespace Drupal\domain_301_redirect\EventSubscriber;
+
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Session\AccountProxyInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\GetResponseEvent;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+/**
+ * Class DomainRedirectEventSubscriber.
+ *
+ * @package Drupal\domain_301_redirect
+ */
+class DomainRedirectEventSubscriber implements EventSubscriberInterface {
+
+  /**
+   * The config factory object.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configFactory;
+
+  /**
+   * Current request.
+   *
+   * @var \Symfony\Component\HttpFoundation\Request
+   */
+  protected $request;
+
+  /**
+   * Current user acocunt.
+   *
+   * @var \Drupal\Core\Session\AccountProxyInterface
+   */
+  protected $userAccount;
+
+  /**
+   * DomainRedirectEventSubscriber constructor.
+   *
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   Config factory object.
+   * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
+   *   The request stack.
+   * @param \Drupal\Core\Session\AccountProxyInterface $user_account
+   *   The current user object.
+   */
+  public function __construct(ConfigFactoryInterface $config_factory, RequestStack $request_stack, AccountProxyInterface $user_account) {
+    $this->configFactory = $config_factory;
+    $this->request = $request_stack->getCurrentRequest();
+    $this->userAccount = $user_account;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  static public function getSubscribedEvents() {
+    $events['kernel.request'] = ['requestHandler'];
+
+    return $events;
+  }
+
+  /**
+   * This method is called whenever the kernel.request event is dispatched.
+   *
+   * @todo Needs a service which will handle the exclusion/inclusion of
+   * the mentioned path/page.
+   *
+   * @param GetResponseEvent $event
+   *   The response event.
+   */
+  public function requestHandler(GetResponseEvent $event) {
+    // If user has 'bypass' permission, then no need to process further.
+    if ($this->userAccount->hasPermission('bypass domain 301 redirect')) {
+      return;
+    }
+
+    // Get config settings of domain_301_redirect module.
+    $domain_config = $this->configFactory->get('domain_301_redirect.settings')->getRawData();
+    // If domain redirection is not enabled, then no need to process further.
+    if (!$domain_config['enabled']) {
+      return;
+    }
+
+    // If domain doesn't contain http/https, then add those to domain.
+    if (!preg_match('|^https?://|', $domain_config['domain'])) {
+      $domain_config['domain'] = 'http://' . $domain_config['domain'];
+    }
+
+    // Parse the domain to get various settings like port.
+    $domain_parts = parse_url($domain_config['domain']);
+    $parsed_domain = $domain_parts['host'];
+    $parsed_domain .= !empty($domain_parts['port']) ? ':' . $domain_parts['port'] : '';
+
+    // If we're not on the same host, the user has access and this page isn't
+    // an exception, redirect.
+    if (($parsed_domain != $this->request->server->get('HTTP_HOST'))) {
+      $uri = $this->request->getRequestUri();
+      $response = new RedirectResponse($domain_config['domain'] . $uri, 301);
+      $response->send();
+    }
+  }
+
+}
diff --git a/src/Form/Domain301RedirectConfigForm.php b/src/Form/Domain301RedirectConfigForm.php
index 440bac3..5ad471b 100644
--- a/src/Form/Domain301RedirectConfigForm.php
+++ b/src/Form/Domain301RedirectConfigForm.php
@@ -64,7 +64,7 @@ class Domain301RedirectConfigForm extends ConfigFormBase {
     $form['check_period'] = [
       '#type' => 'select',
       '#title' => $this->t('Domain Check'),
-      '#description' => $this->t('This option selects the period between domain validation checks. If the Domain no longer points to this site, Domain 301 Redirection will be disabled.'),
+      '#description' => $this->t('This option selects the period between domain validation checks. If the Domain no longer points to this site, Domain 301 Redirection will be disabled. *NOT IMPLEMENTED*'),
       '#options' => [
         0 => $this->t('Disabled'),
         3600 => $this->t('1 hour'),
@@ -79,14 +79,14 @@ class Domain301RedirectConfigForm extends ConfigFormBase {
     $form['domain_check_retries'] = [
       '#type' => 'select',
       '#title' => $this->t('Domain retries'),
-      '#description' => $this->t('Number of times to check domain availability before disabling redirects.'),
+      '#description' => $this->t('Number of times to check domain availability before disabling redirects. *NOT IMPLEMENTED*'),
       '#options' => [1 => 1, 2 => 2, 3 => 3],
       '#default_value' => $config->get('domain_check_retries'),
     ];
     $form['domain_check_reenable'] = [
       '#type' => 'checkbox',
       '#title' => $this->t('Re-enable domain redirection'),
-      '#description' => $this->t('Turn domain redirection on when the domain becomes available.'),
+      '#description' => $this->t('Turn domain redirection on when the domain becomes available. *NOT IMPLEMENTED*'),
       '#default_value' => $config->get('domain_check_reenable'),
     ];
 
@@ -94,16 +94,16 @@ class Domain301RedirectConfigForm extends ConfigFormBase {
     $form['applicability']['path'] = [
       '#type' => 'fieldset',
       '#title' => $this->t('Pages'),
-      '#collapsible' => TRUE,
-      '#collapsed' => FALSE,
+      '#description' => $this->t('*NOT IMPLEMENTED*'),
       '#weight' => 0,
+      '#open' => TRUE,
     ];
 
     $options = [
-      BLOCK_VISIBILITY_NOTLISTED => $this->t('All pages except those listed'),
-      BLOCK_VISIBILITY_LISTED => $this->t('Only the listed pages'),
+      0 => $this->t('All pages except those listed'),
+      1 => $this->t('Only the listed pages'),
     ];
-    $description = $this->t("Specify pages by using their paths. Enter one path per line. The '*' character is a wildcard. Example paths are %blog for the blog page and %blog-wildcard for every personal blog. %front is the front page.", [
+    $description = $this->t('Specify pages by using their paths. Enter one path per line. The \'*\' character is a wildcard. Example paths are %blog for the blog page and %blog-wildcard for every personal blog. %front is the front page.', [
       '%blog' => 'blog',
       '%blog-wildcard' => 'blog/*',
       '%front' => '<front>',