 2.   TCP/IP____________________________105

 

  SPF     OSPF.  -
      . -
,      , 
    SPF.

  -  SPF  ,  
     ,    -
      ,    -
.

      ,
    (hello protocol) OSPF, 
  (neighbor).       ,
        .
     
       .    
 ,      -
 ,      , 
  .

  ,     , -
     (LSA  messages).  
      
      .   
   .  LSA-  -
     ( ). -
 LSA     ,    -
- .

     AS,   -
       AS.  -
      ,  -
 OSPF       , ,
   EGP  BGP.

   AS       -
      . 
   ,      . 
         -
   .   ,   -
    ,   
   .

   ,       -
 (. .    backbone,  ,  
 ),       (,
,   . .)     -
  ,    .