© 1999, Cisco Systems, Inc. ICND—12-1 Routing Protocol (RIP) RIP - RIP 은 Distance Vector...
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Transcript of © 1999, Cisco Systems, Inc. ICND—12-1 Routing Protocol (RIP) RIP - RIP 은 Distance Vector...
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-1
Routing Protocol (RIP)Routing Protocol (RIP)
RIP
- RIP 은 Distance Vector Routing Protocol.
- RIP 은 v1 과 v2 가 있다 .
- Routing 정보 전송을 위해 UDP 포트 520 번 사용
- AD 값은 120
< 장점 >
- 설정이 간단하다 .
- 작은 규모의 네트워크나 대형 네트워크의 말단 지점에서 사용하기 좋다 .
- 표준 Routing Protocol 이기 때문에 모든 회사의 Router 에서 사용 가능
(EIGRP 경우에는 Cisco 전용 , 때문에 다른 회사의 Router 에서는 사용 불가 )
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-2
Routing Protocol (RIP)Routing Protocol (RIP)
RIP
< 단점 >
- Metric 을 Hop-count 로 사용한다 . ( 가장 적은 Hop-count 를 가진 경로가 최적 경로 )
때문에 경로 결정시 Link 의 속도를 반영하지 못한다 .
복잡한 네트워크에서는 비효율적인 Routing 경로가 만들어질 수 있다 .
- RIP 의 최대 Hop-count 가 15, 때문에 대형 네트워크에서는 사용이 불가능 . (Hop-count 가 16 이면 도달 불가능한 네트워크로 간주 )
- Routing 정보 전송 방식이 비효율적이다 .
Topology 에 변화와 상관없이 무조건 30 초마다 인접 Router 에게 Routing table 내용 전체를 전송한다 .
(OSPF, EIGRP, BGP 등의 다른 Dynamic Routing Protocol 은 Topology 변화가 생길 경우 바뀐 네트워크의 정보만 전송 )
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-3
• Hop count metric selects the path
• Routes update every 30 seconds
19.2 kbps
T1
T1 T1
Routing Protocol (RIP)Routing Protocol (RIP)
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-4
Distance Vector—Selecting Best Route with Metrics
Distance Vector—Selecting Best Route with Metrics
Information used to select the best path for routing
56T1
56
T1Cost (Bandwidth)Cost (Bandwidth)
B
A
Hop countHop count
OSPF
RIP
EIGRP
Bandwidth
Delay
Load
Reliability
MTU
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-5
Distance Vector Routing Protocols
Distance Vector Routing Protocols
- Distance Vector Routing Protocol 은 Neighbor Router 에게 주기적으로 Routing Table 을 Update. ( RIP 30 초 , IGRP 90초 )
CC
DD
BB
AA
CC BB AADD
RoutingTable
RoutingTable
RoutingTable
RoutingTable
RoutingTable
RoutingTable
RoutingTable
RoutingTable
Distance—How farVector—In which direction
Distance—How farVector—In which direction
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-6
Routers discover the best path to destinations from each neighbor
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0
Routing TableRouting Table
10.2.0.010.2.0.0
10.3.0.010.3.0.0
00
00S0
S1
Routing TableRouting Table
10.3.0.010.3.0.0 S0 00
10.4.0.010.4.0.0 E0 00
Routing TableRouting Table
10.1.0.010.1.0.0
10.2.0.010.2.0.0
E0
S0
0
0
Distance Vector—Sources of Information and Discovering Routes
Distance Vector—Sources of Information and Discovering Routes
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-7
Routers discover the best path to destinations from each neighbor
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0
Routing TableRouting Table
10.1.0.010.1.0.0
10.2.0.010.2.0.0
10.3.0.010.3.0.0
Routing TableRouting Table
10.2.0.010.2.0.0
10.3.0.010.3.0.0
10.4.0.010.4.0.0
10.1.0.010.1.0.0
00
00
11
11
S0
S1
S1
S0
Routing TableRouting Table
10.3.0.010.3.0.0 S0 00
10.4.0.010.4.0.0 E0 00
10.2.0.010.2.0.0 S0
11
E0
S0
S0 11
0
0
Distance Vector—Sources of Information and Discovering Routes
Distance Vector—Sources of Information and Discovering Routes
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-8
Distance Vector—Sources of Information and Discovering Routes
Distance Vector—Sources of Information and Discovering Routes
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0
Routing TableRouting Table
10.1.0.010.1.0.0
10.2.0.010.2.0.0
10.3.0.010.3.0.0
10.4.0.010.4.0.0
Routing TableRouting Table
10.2.0.010.2.0.0
10.3.0.010.3.0.0
10.4.0.010.4.0.0
10.1.0.010.1.0.0
00
00
11
11
S0
S1
S1
S0
Routing TableRouting Table
10.3.0.010.3.0.0 S0 00
10.4.0.010.4.0.0 E0 00
10.2.0.010.2.0.0 S0
10.1.0.010.1.0.0 S0
11
22
E0
S0
S0
S0
11
22
0
0
Routers discover the best path to destinations from each neighbor
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-9
Routing Protocol (RIP)Routing Protocol (RIP)
RIP version
(1) RIP Version 1
- Subnet mask 정보가 없는 Classful 라우팅 프로토콜 . (VLSM 미지원 )
- 정보 전송 시 Broadcast 주소 (255.255.255.255) 를 사용 . 때문에 RIP 이 설정 안된 다른 장비에게도 불필요한 부하가 걸리게 된다 .
(2) RIP Version 2
- Subnet mask 정보가 있는 Classless 라우팅 프로토콜 (VLSM 지원 )
- 정보 전송 시 Multicast(224.0.0.9) 를 사용한다 .
- 각 라우터에서 네트워크 경로 정보에 대한 인증을 할 수 있다 . 보완성 강화
- tag( 꼬리표 ) 사용이 가능
- Auto Summary ( 자동 축약 ) 를 한다 .
- Manual Summary ( 수동 축약 ) 가 가능하다 .
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-10
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
Convergence ( 수렴 ) Time
- Convergence 네트워크에 변화가 생길 경우 모든 Router 가 네트워크 변화 상태에 대해 정확하고 일관된 정보를 유지하는 것 .
- Convergence Time 네트워크에 변화가 생겼을 경우 그 변화된 정보를 서로 인식하고 수정하는 시간
Convergence Time 은 각 Routing Protocol 별로 다르다 .
Convergence Time 은 짧을 수록 좋다 .
- RIP 같은 경우는 Convergence Time 이 30 초 .
* RIP 같은 경우는 Convergence Time 이 30 초로 느리다 . 때문에 Routing Loop 문제가 발생한다 .
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-11
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
Routing Table
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-12
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
Router C 의 10.4.0.0 Network 장애발생
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-13
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
• Router C 는 10.4.0.0 Network 의 best path 를 router B 에서 찾음
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-14
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
• Router A 는 Router B 로 부터 잘못된 Update 를 받음 .
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-15
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
Network 10.4.0.0 의 잘못된 정보가 계속 Update 됨 .
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-16
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
16 Hop (Hop-Count-Limit)
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-17
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
• Packet 은 10.4.0.0 으로 가기 위해서 Router B 와 Router C 사이에서 계속 Loop 됨
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-18
Maintaining Routing Information Problem—Routing Loops
Maintaining Routing Information Problem—Routing Loops
- 해결책 -
1)Split Horizon
2) Route Poisoning, Poison reverse
3) Hold Down Timer
4) Triggered Update
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-19
Solution: Split HorizonSolution: Split Horizon
It is never useful to send information about a route back in the direction from which the original packet came
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0 XXXXXX
Routing TableRouting Table
10.3.0.0 S0
S0
S0
S0
11
2210.1.0.0
10.2.0.0
10.4.0.0
0
0
Routing TableRouting Table
E0
S0
S0
S0
11
22
10.1.0.0
10.4.0.0
10.3.0.0
10.2.0.0
0
0
Routing TableRouting Table
S0
S1
S1
E1
11
22
10.2.0.0
10.1.0.0
10.4.0.0
10.3.0.0
0
0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-20
Solution: Route PoisoningSolution: Route Poisoning
Routers set the distance of routes that have gone down to infinity
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0 XX
Routing TableRouting Table
10.3.0.0
S0
S0
S0
S0
11
2210.1.0.0
10.2.0.0
10.4.0.0
0
Infinity
Routing TableRouting Table
10.1.0.0E0
S0
S0
S0
11
2210.4.0.0
10.3.0.0
10.2.0.0
0
0
Routing TableRouting Table
10.2.0.0S0
S1
S1
E1
11
2210.1.0.0
10.4.0.0
10.3.0.0
0
0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-21
Solution: Poison ReverseSolution: Poison Reverse
Poison Reverse overrides split horizon
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0 XX
Routing TableRouting Table
10.3.0.0
S0
S0
S0
S0
11
2210.1.0.0
10.2.0.0
10.4.0.0
0
Infinity
Routing TableRouting Table
10.1.0.0E0
S0
S0
S0
11
2210.4.0.0
10.3.0.0
10.2.0.0
0
0
Routing TableRouting Table
10.2.0.0S0
S1
S1
E1
PossiblyDown
PossiblyDown
2210.1.0.0
10.4.0.0
10.3.0.0
0
0
PoisonReverse
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-22
Solution: Hold-Down TimersSolution: Hold-Down Timers
Router keeps an entry for the network possibly down state, allowing time for other routers to recompute for this topology change
Network 10.4.0.0 is downthen back up
then back down
Update afterhold-down Time
Update afterhold-down Time
Network 10.4.0.0is unreachable
Network 10.4.0.0is unreachable
AA BB CC
10.1.0.0 10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0 XXUpdate after
hold-down TimeUpdate after
hold-down Time
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-23
Solution: Triggered UpdatesSolution: Triggered Updates
Router sends updates when a change in its routing table occurs
AA BB CC
10.2.0.0 10.3.0.0 10.4.0.0
E0 S0 S0 S1 S0 E0 XX
Network 10.4.0.0is unreachable
Network 10.4.0.0is unreachable
Network 10.4.0.0is unreachable
Network 10.4.0.0is unreachable
Network 10.4.0.0is unreachable
Network 10.4.0.0is unreachable
10.1.0.0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-25
Implementing Solutions in Multiple Routes
Implementing Solutions in Multiple Routes
DD
BBEE
AA
XX CC
10.4.0.0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-26
Implementing Solutions in Multiple Routes (cont.)
Implementing Solutions in Multiple Routes (cont.)
DD
BBEE
AA
CCXX10.4.0.0
HolddownHolddown
HolddownHolddown
HolddownHolddown
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-27
Implementing Solutions in Multiple Routes (cont.)
Implementing Solutions in Multiple Routes (cont.)
DD
BBEE
AA
CCXX10.4.0.0
HolddownHolddown
HolddownHolddown
HolddownHolddown
Poison ReversePoison Reverse
Poison ReversePoison Reverse
Poison ReversePoison Reverse
Poison ReversePoison Reverse
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-28
Implementing Solutions in Multiple Routes (cont.)
Implementing Solutions in Multiple Routes (cont.)
DD
BBEE
AA
CCXX10.4.0.0
HolddownHolddown
HolddownHolddown
HolddownHolddown
Packet for Network 10.4.0.0
Packet for Network 10.4.0.0
Packet for Network 10.4.0.0
Packet for Network 10.4.0.0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-29
Implementing Solutions in Multiple Routes (cont.)
Implementing Solutions in Multiple Routes (cont.)
DD
BBEE
AA
CCLink up!Link up!
10.4.0.0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-30
Implementing Solutions in Multiple Routes (cont.)
Implementing Solutions in Multiple Routes (cont.)
DD
BBEE
AA
CCLink up!
10.4.0.0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-31
•Starts the RIP routing process
Router(config)#router rip
Router(config-router)#network network-number
• Selects participating attached networks• The network number must be a major classful
network number
RIP ConfigurationRIP Configuration
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-32
2.3.0.0router ripnetwork 172.16.0.0network 10.0.0.0
RIP Configuration ExampleRIP Configuration Example
router ripnetwork 10.0.0.0
2.3.0.0router ripnetwork 192.168.1.0network 10.0.0.0
172.16.1.1
S2E0 S3
192.168.1.110.1.1.1 10.2.2.210.1.1.2
S2 S3
10.2.2.3172.16.1.0 A B C
192.168.1.0 E0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-33
Verifying the Routing Protocol—RIP
Verifying the Routing Protocol—RIP
RouterA#sh ip protocolsRouting Protocol is "rip" Sending updates every 30 seconds, next due in 0 seconds Invalid after 180 seconds, hold down 180, flushed after 240 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Redistributing: rip Default version control: send version 1, receive any version Interface Send Recv Key-chain Ethernet0 1 1 2 Serial2 1 1 2 Routing for Networks: 10.0.0.0 172.16.0.0 Routing Information Sources: Gateway Distance Last Update 10.1.1.2 120 00:00:10 Distance: (default is 120)
172.16.1.1
S2E0 S3
192.168.1.110.1.1.1 10.2.2.210.1.1.2
S2 S3
10.2.2.3172.16.1.0 A B C
192.168.1.0 E0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-34
Displaying the IP Routing TableDisplaying the
IP Routing Table
RouterA#sh ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route, o - ODR T - traffic engineered route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 1 subnetsC 172.16.1.0 is directly connected, Ethernet0 10.0.0.0/24 is subnetted, 2 subnetsR 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2C 10.1.1.0 is directly connected, Serial2R 192.168.1.0/24 [120/2] via 10.1.1.2, 00:00:07, Serial2
172.16.1.1
S2E0 S3
192.168.1.110.1.1.1 10.2.2.210.1.1.2
S2 S3
10.2.2.3172.16.1.0 A B C
192.168.1.0 E0
© 1999, Cisco Systems, Inc. www.cisco.com ICND—12-35
debug ip rip Commanddebug ip rip Command
RouterA#debug ip ripRIP protocol debugging is onRouterA#00:06:24: RIP: received v1 update from 10.1.1.2 on Serial200:06:24: 10.2.2.0 in 1 hops00:06:24: 192.168.1.0 in 2 hops00:06:33: RIP: sending v1 update to 255.255.255.255 via Ethernet0 (172.16.1.1)00:06:34: network 10.0.0.0, metric 100:06:34: network 192.168.1.0, metric 300:06:34: RIP: sending v1 update to 255.255.255.255 via Serial2 (10.1.1.1)00:06:34: network 172.16.0.0, metric 1
172.16.1.1
S2E0 S3
192.168.1.110.1.1.1 10.2.2.210.1.1.2
S2 S3
10.2.2.3172.16.1.0 A B C
192.168.1.0 E0