SPF

SPF

5

, .

, SPT , . . , G 2001: db8: 3e8: 100 :: / 64. A . - , , (, Ethernet). SPT, ( ) . (IP- - ) (, , - ). SPT.

   SPF

, [C, E] . ? , C, B D , A . A E. , :

  • , E.
  • C ( A), , , E , [C, E] .

SPF.


LFA rLFA.

( ) , LFA rLFA. Bellman-Ford , LFA, , , . DUAL . (, , SPF)? , LFA .

 LFA

- , , . :

  • A SPT, SPF .
  • A B C, , [A, B] [A, C] .

, A , , - . LFA:

, , LFA.

, :

  • NC - .
  • BC - .
  • LC - .

NC + BC < LC, LFA. A [B, A] [C, A] ( , SPT ). , LFA , LFA? P/Q Space LFA. P/Q Space.

P - , , Q - , . :

SPT , ; SPT. .

 P/Q    LFA

E :

  • Q, [E, D] SPT , E D.
  • P, SPT D ( D ), [D, E], , D E.
  • , E, D, [E, D].

SPF - , Shortest Path Trees .


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