---------           ------             ---------
         /   RR....\.mh-ebpg /      \    mh-ebgp/....RR   \
        /    :      \    `. /        \ .'      /      :    \
       | PE1 o    ASBR1 -- ASBR2    ASBR3 -- ASBR4    o PE2 |
        \           /       \        /         \           /
         \         /         \      /           \         /
          ---------           ------             ---------
          AS 100              AS 200              AS 300
       |-------------------|----------|---------------------|
          segment 1          segment 2         segment 3