[#3082] updated D2 docs

Author: Razvan Becheriu

doc/sphinx/arm/ddns.rst

@@ -319,6 +319,8 @@ operating system, i.e. the size of the ``sun_path`` field in the
 different operating systems, between 91 and 107 characters. Typical
 values are 107 on Linux and 103 on FreeBSD.
 
+Kea supports only one ``unix`` control socket in the "control-sockets" list.
+
 Communication over the control channel is conducted using JSON structures.
 See the `Control Channel section in the Kea Developer's
 Guide <https://reports.kea.isc.org/dev_guide/d2/d96/ctrlSocket.html>`__
@@ -424,6 +426,9 @@ password, these values can be read from files. The syntax is extended by:
 -  The ``user-file`` client parameter, which, with the ``directory`` parameter,
    specifies the path of a file where the user ID can be read.
 
+Since Kea-2.7.6 Kea supports multiple HTTP/HTTPS connections.
+Both IPv4 and IPv6 addresses can be used.
+
 When files are used, they are read when the configuration is loaded,
 to detect configuration errors as soon as possible.
 
@@ -448,6 +453,11 @@ to detect configuration errors as soon as possible.
                        "password": "1234"
                    } ]
                }
+           },
+           {
+               "socket-type": "http",
+               "socket-address": "2010:30:40::50",
+               "socket-port": 8004
            }
        ],
        ...

src/lib/config/unix_command_config.h

@@ -81,6 +81,8 @@ class UnixCommandConfig : public isc::data::UserContext,
 /// @brief Pointer to a UnixCommandConfig object.
 typedef boost::shared_ptr<UnixCommandConfig> UnixCommandConfigPtr;
 
+/// @brief Structure used to store UNIX connection data.
+/// (configuration, acceptor, etc.)
 struct UnixSocketInfo {
     /// @brief Flag which indicates if socket can be reused.
     bool usable_;