1 Module 03 Routing Protocol Chapter 10 RIP, IGRP, and Static Route Concepts and Configuration 2 Objectives  Upon completion of this chapter, you will be able to complete the following tasks:  Distinguish the use and operation of static and dynamic routes  Configure and verify a static route  Identify how distance vector IP routing protocols such as RIP and IGRP operate on Cisco routers  Enable Routing Information Protocol (RIP)  Enable Interior Gateway Routing Protocol (IGRP)  Verify IP routing with show and debug commands 3  To route, a router needs to know:  Destination addresses  Sources it can learn from  Possible routes  Best route  Maintain and verify routing information What is Routing? 172.16.1.010.120.2.0 4 What is Routing? (cont.) Network Protocol Destination Network Connected Learned 10.120.2.0 172.16.1.0 Exit Interface E0 S0 Routed Protocol: IP Routers must learn destinations that are not directly connected 172.16.1.010.120.2.0 E0 S0 5  Static Route Uses a route that a network administrator enters into the router manually  Dynamic Route Uses a route that a network routing protocol adjusts automatically for topology or traffic changes Identifying Static and Dynamic Routes 6 172.16.2.1 SO Static Routes 172.16.1.0 B 172.16.2.2 Network A Configure unidirectional static routes to and from a stub network to allow communications to occur. B Stub Network 7 Defines a path to an IP destination network or subnet Router(config)#ip route network [mask] {address | interface}[distance] [permanent] Static Route Configuration 8 Stub Network ip route 172.16.1.0 255.255.255.0 172.16.2.1 172.16.2.1 SO Static Route Example 172.16.1.0 B 172.16.2.2 Network A B  This is a unidirectional route. You must have a route configured in the opposite direction. 10.0.0.0 9 Stub Network ip route 0.0.0.0 0.0.0.0 172.16.2.2 Default Routes 172.16.2.1 SO 172.16.1.0 B 172.16.2.2 Network A B  This route allows the stub network to reach all known networks beyond router A. 10.0.0.0 10 What is a Routing Protocol?  Routing protocols are used between routers to determine paths and maintain routing tables.  Once the path is determined a router can route a routed protocol. Network Protocol Destination Network Connected RIP IGRP 10.120.2.0 172.16.2.0 172.17.3.0 Exit Interface E0 S0 S1 Routed Protocol: IP Routing protocol: RIP, IGRP 172.17.3.0 172.16.1.010.120.2.0 E0 S0 [...]... 192.168.1.0 RouterA#sh ip route Codes: 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... Router(config-router)#network network-number  • Mandatory configuration command for each IP routing process • Identifies the physically connected network 28 RIP Overview 19.2 kbps T1 T1 T1  Maximum six paths (default = 4)  Hop count metric selects the path  Routes update every 30 seconds 29 RIP Configuration Router(config)#router rip Starts the RIP routing process Router(config-router)#network network-number • Selects... S0 C E0 X  Router sends updates when a change in its routing table occurs 26 IP Routing Configuration Tasks Network 172.16.0.0 RIP  Router configuration  Select routing protocols  Specify networks or interfaces IGRP, RIP IGRP Network 160.89.0.0 RIP Network 172.30.0.0 27 Dynamic Routing Configuration Router(config)#router protocol [keyword] Defines an IP routing protocol Router(config-router)#network... within an autonomous system  EGPs connect different autonomous systems 11 Administrative Distance: Ranking Routes I need to send a packet to Network E Both router B IGRP Administrative Distance=100 and C will get it there Which route is best? Router A Router B RIP Administrative Distance=120 E Router C Router D 12 Classes of Routing Protocols B Distance Vector A C D Hybrid Routing B A C Link State D 13... Topology change causes routing table update  Updates proceed step-by-step from router to router 17 Maintaining Routing Information Problem— Routing Loops 10.1.0.0 E0 10.2.0.0 A S0 Routing Table 10.3.0.0 S0 B S1 Routing Table 10.4.0.0 S0 C E0 X Routing Table 1 1 1 2 1 2 Router C concludes that the best path to network 10.4.0.0 is through Router B 18 Maintaining Routing Information Problem— Routing Loops... neighbor routers and accumulate distance vectors 14 Distance Vector—Sources of Information and Discovering Routes 10.1.0.0 E0 10.2.0.0 A S0 Routing Table S0 10.3.0.0 B S1 Routing Table 10.4.0.0 S0 C E0 Routing Table 10.1.0.0 E0 0 10.2.0.0 S0 0 10.3.0.0 S0 0 10.2.0.0 S0 0 10.3.0.0 S1 0 10.4.0.0 E0 0  Routers discover the best path to destinations from each neighbor 15 Distance Vector—Selecting Best Route. .. Poison Reverse overrides split horizon 24 Solution: Hold-Down Timers Network 10.4.0.0 is unreachable Update after hold-down Time 10.1.0.0 10.2.0.0 E0 A S0 Update after hold-down Time S0 10.3.0.0 B S1 10.4.0.0 S0 C E0 X Network 10.4.0.0 is down then back up then back down  Router keeps an entry for the network possibly down state, allowing time for other routers to recompute for this topology change 25 Solution:... attached networks • The network number must be a major classful network number 30 RIP Configuration Example E0 172.16.1.0 S2 S2 A 172.16.1.1 10.1.1.1 2.3.0.0 router rip network 172.16.0.0 network 10.0.0.0 10.1.1.2 S3 B S3 E0 C 10.2.2.2 10.2.2.3 192.168.1.1 192.168.1.0 2.3.0.0 router rip network 192.168.1.0 network 10.0.0.0 router rip network 10.0.0.0 31 Verifying the Routing Protocol—RIP E0 172.16.1.0 S2... about a route back in the direction from which the original packet came 22 Solution: Route Poisoning 10.1.0.0 E0 10.2.0.0 A S0 Routing Table 10.3.0.0 S0 B S1 Routing Table 10.4.0.0 S0 C E0 X Routing Table 10.1.0.0E0 0 10.2.0.0S0 0 10.3.0.0 S0 10.2.0.0S0 0 10.3.0.0S1 0 10.4.0.0 S0 Infinity 0 10.3.0.0S0 1 10.4.0.0S1 1 10.2.0.0 S0 1 10.4.0.0S0 2 10.1.0.0E1 2 10.1.0.0 S0 2  Routers set the distance of routes... S1 Routing Table 10.4.0.0 S0 C E0 X Routing Table 1 3 1 4 1 2 Router A updates its table to reflect the new but erroneous hop count 19 Symptom: Counting to Infinity 10.1.0.0 E0 10.2.0.0 A S0 Routing Table 10.3.0.0 S0 B S1 Routing Table 10.4.0.0 S0 C E0 X Routing Table 1 5 1 6 1 2  Packets for network 10.4.0.0 bounce between routers A, B, and C  Hop count for network 10.4.0.0 counts to infinity 20 . 1 Module 03 Routing Protocol Chapter 10 RIP, IGRP, and Static Route Concepts and Configuration 2 Objectives  Upon completion of this chapter, you will be able to. the use and operation of static and dynamic routes  Configure and verify a static route  Identify how distance vector IP routing protocols such as RIP and IGRP operate on Cisco routers  Enable. systems 12 Administrative Distance: Ranking Routes IGRP Administrative Distance=100 Router D Router D Router B Router B Router A Router A Router C Router C RIP Administrative Distance=120 E E I