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10 10.1 r o u t e I C M P R I P (Routing Infromation Protocol) T C P / I P O S P F B G P I n t e r n e t B 10.2 routing daemon 9-1 9. 2 I P routing mechanism r o u t e routing policy I n t e r n e t I n t e r n e A S Autonomous System N S F N E T I n t e r n e t I G P Interior Gateway Protocol intradomain routing protocol

96 TCP/IP 1 I G P R I P I G P O S P F Open Shortest Path First R I P 1986 N S F N E T I G P H E L L O RFC [Almquist 1993] OSPF RIP IGP E G P Exterier Gateway Protocol E G P E G P E G P N S F N E T B G P Border Gateway ProtocolB G P E G 10.3 Unix U n i x r o u t e d T C P / I P R I P g a t e d I G P E G P [Fedor 1998] g a t e d 10-1 r o u t e d g a t e d r o u t e d g a t e d routed gated, 2 gated, 3 10-1 r o u t e d g a t e d RIP 1 1 0. 5 R I P 2 10. 6 O S P F 10. 7 B G P 10.4 RIP R I P R I P RFC 1058 [Hedrick 1988a] R F C 10.4.1 RIP UDP 10-2 11 UDP 1 0-3 I P R I IP UDP 1 2 3 4 RIP 5 6 20 8 10-2 UDP RIP

10 97 1 2 R I P 1 0. 5 2 20 address family I P 2I R I P 20 R I P 25 25 R I P 20 25 + 4 = 504 512 25 ( 0) (2) ( 0) 32 IP ( 0) ( 0) (1-16) ( 24 20 ) 10-3 10.4.2 R I P r o u t e d R I P U D P 520 U D P 520 1 0 16 16 16 30

98 TCP/IP 1 R I P 3 16 6 3 0 60 10.4.3 R I P ( h o p ) 1 10-4 4 R I P R2 N3 R 1 N 2 N 2 1 N 1 N 1 N 2 N 1 1 R 2 N 2 1 N 3 1 10-4 1 2 R 2 N 1 2 R 1 N 3 A S A S 15 R I P 15 A S 16 I P 10.4.4 R I P B 16 bit 0 R I P R I P R I P RFC 1058 [Hedrick 1988a] R I P 15 R I P 10.4.5 R1 N1 2 r i p q u e r y g a t e d

10 99 r i p q u e r y 10-3 5 p o l l 5 R I P c o m m a n d 1 0 16 1 0-5 s u n s u n r i p q u e r y n e t b sun % ripquery -n netb 504 bytes from netb (140.252.1.183): 504 140.252.1.0, metric 1 1 0-5 140.252.13.0, metric 1 1 0-5 244 bytes from netb (140.252.1.183): 244 n e t b 1 n e t b 140. 252. 1. 0 m e t r i c 1 n I P n e t b 140. 252. 13 n e t b 140. 252. 13 140. 252. 13 1 0-6 t c p d u m p - i s 10 S L I P 1 R I P 1 5 R I P 2 1 2 24 R I P 20 10-5 n e t b g a t e w a y 3 25 25 504 r i p q u e r y t c p d u m p - s 600 600 U D P R I P 10-6 r i p q u e r y t c p d u m p 4 12 12 20 + 4=244 r i p q u e r y n e t b g a t e w a y 140. 252. 13. 0 2

100 TCP/IP 1 sun % ripquery -n gateway 504 bytes from gateway (140.252.1.4): 140.252.1.0, metric 1 1 0-5 140.252.13.0, metric 2 1 0-5 10-5 140. 252. 1. 0 1 g a t e w a y n e t b 140. 252. 13. 0 2 10.4.6 R I P R I P 10-7 n o a o. e d u R n n I P 10-7 noao.edu 140.252 s o l a r i s Solaris 2.x s n o o p t c p d u m p 10-8 60 Rn P t r udp port 520 520 U D P R 6 R 4 R 2 R 7 R 8 R 3 6 R 2 140. 252. 6. 0 1 R 4 140. 252. 4. 0 1 g a t e w a y 15 s n o o p v R I P I U D P R I P R I P 10-9

10 101 10-8 s o l a r i s 60 RIP 140. 252. 1 10-7 10-8 R 10 4 10-7 3 s n o o p R I P R I P Address Metric RIP: 140.251.0.0 16 (not reachable) RIP: 140.252.9.0 1 RIP: 140.252.10.0 1 RIP: 140.252.11.0 1 B 140. 251 n o a o. e d u 10-9 g a t e w a y RIP 1 0-8 R 10 R I P s n o o p B R O A D C A S T I P 255. 255. 255. 255 1 2. 2

102 TCP/IP 1 140. 252. 1. 255 10.5 RIP 2 RFC 1388 [Malkin 1993a] R I P R I P - 2 10-3 0 R I P 0 R I P R I P - 2 1 0-10 R I P - 2 R I P - 2 (1-6) (2) (2) 32 IP 32 32 IP (1-16) ( 24 20 ) 10-10 RIP-2 (routing domain) U n i x R I P (routing tag) E G P B G P I P I P I P 0 R I P R I P - 2 R I P 20 0 x ffff 2 16 R I P - 2 12 R I P - 10.6 OSPF O S P F R I P R I RFC 1247 [Moy 1991 ] 2 O S P F 20 R I P O S P F R I P

10 103 [ P e r l m a n 1 9 9 2 ] 9. 3 O S P F R I P O S P F I P U D P T C P I P p r o t o c o l O S P F 3-1 O S P F R I P 1) OSPF I P 3-2 I P 2) I P 3) O S P F 4) OSPF I P 3. 7 1 I P 0. 0. 0. 0 0 5) I P I P 6) R I P - 2 10. 5 7) OSPF 12 O S P F O S P F O S P F R I P 10.7 BGP B G P B G P A R PA N E T E G P RFC1267 [Lougheed and Rekhter 1991] 3 B G P RFC 1268 [Rekhter and Gross 1991] I n t e r n e t B G P B G R F C 1993 4 B G P RFC 1467 [To p o l c i c 1993 ] 10. 8 C I D R B G P B G P A S I P I P I P I n t e r n e t B G P

104 TCP/IP 1 1) (stub AS) stub AS 2) (multihomed AS) 3) (transit AS) I n t e r n e t B G P E G P B G P B G P B G B G P R I P O S P F B G P T C P B G T C P B G P B G P R I B G 16 bit B G P k e e p a l i v e T C P 30 k e e p a l i v e T C P k e e p a l i v e 23 10.8 CIDR 3 B C B C B C C I D R I n t e r n e t s u p e r n e t t i n g RFC 1518 [Rekher and Li 1993] RFC 1519 [Fuller et al. 1993] [Ford, Rekhter, and Braun 1993 ] C I D R Internet Architecture Board s blessing [Huitema 1993] R F C 1467 [Topolcic 1993] I n t e r n e t C I D R C I D R I P ( s u m m a r i z a t i o n ) 16 C 16 1 I n t e r n e t 8 I n t e r n e t I n t e r n e 8 I P 8 I n t e r n e t 1) I P I P

10 105 2) 32 bit IP 32 bit 3) 32 bit 32 O S P F 1 0. 6 R I P - 2 1 0. 5 4 B G P 32 bit RFC 1466 [Gerich 1993] C 1 9 4. 0. 0. 0 195. 255. 255. 255 16 0 x c 2000000 0 x c 3 ffffff 65536 C 7 bit I P 0 x c 2000000 32 bit 0xfe000000 (254.0.0.0) 65536 C C 194 1 95 32 bit 7 bit C I D R 32 bit 194. 0. 16. 0 194.0.31.255 (16 C ) I P 1 9 4. 0. 1 6. 0 255.255.240.0 (0xfffff 000 ) 194. 0. 22. 1 C 255. 255. 240 2 54. 0. 0. 0 32 bit IP I A B C C I D R C I n t e r n e t C I D R I P I [Ford, Rekhter, and Braun 1993] 10 000 200 10.9 I G P E G P I G P R I O S P F I G P E G P B G P R I P 2 R I P O S P F B G P C I D R C I D R I n t e r n e t O S I I D R P O S I I P B G Intermediate System to Intermediate System I S - I S O S I I G P C L N P I P O S I I S - I S O S P F [Perlman 1992]

106 TCP/IP 1 10.1 10-9 k p n o g a t e w a y 10.2 R I P 30 25 25 10.3 OSPF R I P 10.4 O S P F 10.5 RFC1058 R I P 10-8 140. 252. 1 10.6 3. 4 10-7 8 140. 252. 1 100 100 30 8 10-8