docs: explain check-connection in generic site conf docs

docs/package/gluon-scheduled-domain-switch.rst

@@ -22,11 +22,6 @@ domain_switch : optional (needed for domains to switch)
     switch_time :
         - UNIX epoch after which domain will be switched
 
-check_connection :
-    targets :
-        - array of IPv6 addresses which are probed to determine if the node can
-          reach any time-servers to acquire the correct time
-
 Example::
 
   domain_switch = {
@@ -42,5 +37,6 @@ Example::
     },
   },
 
-Note: the package ``gluon-check-connection`` is installed as dependency but it can
+Note: the package ``gluon-check-connection`` is installed as dependency so you
-also be used stand-alone, e.g. to detect if a connection to the internet is working.
+have to define ``check_connection`` too. A node is considered online if any of
+the specified ip addresses can be reached via ping.

docs/user/site.rst

@@ -419,6 +419,22 @@ autoupdater \: package
     All configured mirrors must be reachable from the nodes via IPv6. If you don't want to set an IPv6 address
     explicitly, but use a hostname (which is recommended), see also the :ref:`FAQ <faq-dns>`.
 
+.. _user-site-check_connection:
+
+check_connection \: optional
+    ``targets`` defines an array of IPv6 addresses which are probed for
+    connectivity, for example determine if the node can reach any time-servers
+    to acquire the correct time. This is e.g. used for the
+    *gluon-scheduled-domain-switch* package
+    ::
+
+      check_connection = {
+        targets = {
+          '2001:4860:4860::8888',
+          '2001:4860:4860::8844',
+        },
+      },
+
 .. _user-site-config_mode:
 
 config_mode \: optional