2001:db8::1
                       +----------+
                       | R1       |
                       +----------+
                            |
                       +----------+
                       | R2       |  2001:db8::2
                       +----------+
                      *   |   *    *
                     *    |   *     *
                    *link1|   *      *
     2001:db8::4   *      |   *link2  *  2001:db8::5
        +-----------+     |   *     +-----------+
        | R4        |     |   *     | R5        |
        +-----------+     |   *     +-----------+
                   *      |   *      *   +
                    *     |   *     *    +
                     *    |   *    *     +
                     +-----------+   +-----------+
        2001:db8::3  | R3        |   |R6         |2001:db8::6
                     +-----------+   +-----------+
                          |
                     +-----------+
                     | R8        |  2001:db8::8
                     +-----------+