RIPv2 Routing Protocols and Concepts – Chapter 7 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public ITE PC v4.0 Chapter 1 1 Objectives  En cou nt e r a n d desc ri be th e limit a ti o n s o f RIPv1’ s cou e a d desc be e a o s o s limitations.  Apply the basic Routing Information Protocol Version Apply the basic Routing Information Protocol Version 2 (RIPv2) configuration commands and evaluate RIPv2 classless routing updates.  Analyze router output to see RIPv2 support for VLSM and CIDR  Identify RIPv2 verification commands and common RIPv2 issues.  Configure, verify, and troubleshoot RIPv2 in “hands- on” labs ITE PC v4.0 Chapter 1 2 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public Introduction Introduction  Difference between RIPv1 & RIPv2  RIPv1  RIPv1 •A classful distance vector routing protocol • Does not support discontiguous subnets Does not support discontiguous subnets •Does not support VLSM •Does not send subnet mask in routing update •Routing updates are broadcast RIPv2 •A classless distance vector routing protocol that is an enhancement of RIPv1 ’ s features enhancement of RIPv1 s features . •Next hop address is included in updates •Routing updates are multicast (224.0.0.9 vs. 255.255.255.255) http://www.cisco.com/univercd/cc/t d/doc/cisintwk/ito_doc/rip.htm ITE PC v4.0 Chapter 1 3 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public •The use of authentication is an option Introduction  Similarities between RIPv1 & RIPv2 – Use of timers to prevent routing loops Use of timers to prevent routing loops – Use of split horizon or split horizon with poison reverse to also help prevent routing loops. – Use of triggered updates when there is a change in the topology for faster convergence. Maximum hop count of 15 with the hop count of 16 signifying – Maximum hop count of 15 , with the hop count of 16 signifying an unreachable network. ITE PC v4.0 Chapter 1 4 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public RIP 1 Li it ti RIP v 1 Li m it a ti ons  Lab Topology 3t t  3 rou t er se t up Topology is discontiguous There exists a static summary route Static route information can be injected into routing table updates using redistribution.  Routers 1 & 3 contain VLSM Routers 1 & 3 contain VLSM networks Remember that both the R1 and R3 routers have subnets that are part of the 172 30 0 0/16 major classful the 172 . 30 . 0 . 0/16 major classful network (class B). Also remember that R1 and R3 are connected to R2 usin g subnets of the g 209.165.200.0/24 major classful network (class C). This topology is discontiguous and will not converge because ITE PC v4.0 Chapter 1 5 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public will not converge because 172.30.0.0/16 is divided by the 209.165.200.0/24. RIP 1 Li it ti RIP v 1 Li m it a ti ons  The topology shows that R2 has a static R2 has a static summary route to the 192.168.0.0/16 network. The configuration of this summar y route will be ITE PC v4.0 Chapter 1 6 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public y displayed later in this section. RIP 1 Li it ti RIP v 1 Li m it a ti ons  Review the VLSM addressing scheme in the figure As shown scheme in the figure . As shown in the top chart, both R1 and R3 have had the 172.30.0.0/16 network subnetted into /24 subnets subnets . –Four of these /24 subnets are assigned: – two to R1 ( 172.30.1.0/24 and ( 172.30.2.0/24) –two to R3 (172.30.100.0/24 and 172.30.110.0/24). Ithbtt ht h  I n th e b o tt om c h ar t , we h ave taken the 172.30.200.0/24 subnet and subnetted it again, usin g the first four bits for g subnets and the last four bits for hosts. The result is a 255.255.255.240 mask or /28. Subnet 1 and Subnet 2 are ITE PC v4.0 Chapter 1 7 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public Subnet 1 and Subnet 2 are assigned to R3. RIP 1 Limitations RIP v 1 Limitations  Scenario Continued S  VL S M -Recall this is sub netting the subnet  Private IP addresses are on LAN links  Public IP addresses are used on WAN links (through an ISP, or when inside users dt t id it nee d t o access ou t s id e s it es, a public IP address must be used.)  Loopback interfaces -These are virtual interfaces that can be pinged and ITE PC v4.0 Chapter 1 8 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public that can be pinged and added to routing table Cisco has set these addresses aside for educational purposes. RIPv1 Limitations  Loopback interfaces Notice that R3 is using loopback interfaces (Lo0, Lo1, and Lo2). A loopback interface is a software-only interface that is used to emulate a physical interface is used to emulate a physical interface . Like other interfaces, it can be assigned an IP address. Loopback interfaces are also used by other routing p rotocols , such as OSPF , for different p ur p oses. p, , pp These uses will be discussed in Chapter 11 OSPF. In a lab environment, loopback interfaces are useful in creating additional networks without having to add more physical interfaces on the router more physical interfaces on the router . A loopback interface can be pinged and the subnet can be advertised in routing updates.  Therefore, loopback interfaces are ideal for Therefore, loopback interfaces are ideal for simulating multiple networks attached to the same router. In our example, R3 does not need four LAN interfaces to demonstrate multiple subnets and ITE PC v4.0 Chapter 1 9 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public interfaces to demonstrate multiple subnets and VLSM. Instead, we use loopback interfaces. RIPv1 Limitations RIPv1 Limitations  Route redistribution Redistribution involves taking the routes from one routing – Redistribution involves taking the routes from one routing source and sending those routes to another routing source. • In our example topology, we want the RIP process on R2 to redistribute our static route (192.168.0.0/16) by importing the route into RIP and then sending it to R1 and R3 using the RIP process. R2( fi t)#ditibt tti - R2( con fi g-rou t er )# re di s t r ib u t e s t a ti c ITE PC v4.0 Chapter 1 10 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public [...]... all of which are members of the class B network 172 .30.0.0/16: –1 72 .30.100.0/24 (FastEthernet 0/0) 172 .30.100.0/24 –1 72 .30.110.0/24 (Loopback 0) –1 72 .30.200.16/28 (Loopback 1) –1 72 .30.200.32/28 (L 172 30 200 32/28 (Loopback 2) b k As we saw with the 172 .30.0.0/16 updates to R2 by R3, p y –RIPv1 either summarizes the subnets to the classful boundary –or uses t e sub et mask o t e o the subnet as of... to advertise ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 17 RIPv1 Limitations Why is RIPv1 on R3 not including the other subnets, 172 .30.200.16/28 172 30 200 16/28 and 172 .30.200.32/28, in updates to R4? – Those subnets do not have the same subnet mask as FastEthernet 0/0 – R3 will only include those 172 .30.0.0 172 30 0 0 routes in its routing table with the same... 0/0/1 from R3 ITE PC v4.0 Chapter 1 R2 has two equal cost routes to the 172 .30.0.0/16 network © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 15 RIPv1 Limitations RIP 1 Li it ti •R1 has its own 172 30 0 0 routes: 172 .30.0.0 172 .30.2.0/24 and 172 .30.1.0/24 •But R1 does not send R2 those subnets •R3 has a similar routing table •Both R1 and R3 are b B th d boundary routers and d t d are only sending... exit interface – Since the interface is 172 .30.100.1 with a /24 mask, it will only i l d ith k ill l include 172 .30.0.0 subnets with a /24 mask The only one that meets this condition is 172 .30.110.0 – The other 172 .30.0.0 subnets, 172 .30.200.16/28 and 172 .30.200.32/28, are not included because the /28 masks do not match the /24 mask of the outgoing interface ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems,... VLSM, or CIDR –if network i di if t k is discontiguous and RIP 1 configured convergence will not b ti d RIPv1 fi d ill t be reached –RIPv1 on both the R1 and R3 routers will summarize their 172 .30.0.0 subnets to the classful major network address of 172 30 0 0 when sending 172 .30.0.0 routing updates to R2 –From the perspective of R2, both updates have an equal cost of 1 hop to reach network 172 30 0 0/16... the 172 .30.0.0/16 see, routing table ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 14 RIPv1 Limitations RIP 1 Li it ti Examining the routing tables -To examine the contents of routing updates use the debug ip rip command R2 is receiving two 172 .30.0.0 equal cost i i i t 172 30 0 0 l t routes with a metric of 1 hop R2 is receiving one route on Serial 0/0/0 from R1 and. .. summarized 172 .30.0.0 network to R2 in their RIPv1 routing updates •As a result, R2 only k A lt l knows about th b t the 172 .30.0.0/16 classful network and is unaware of any 172 .30.0.0 subnets ITE PC v4.0 Chapter 1 •R2 that it is not including the 172 .30.0.0 network in its updates to either R1 or R3 •Because the split horizon rule is in effect •R2 learned about 172 30 0 0/16 on both the 172 .30.0.0/16... attempting to ping the 172 .30.100.1 on R3 R3 is able to ping 10 1 0 1 but is unsuccessful 10.1.0.1 when attempting to ping the 172 .30.1.1 on R1 ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 13 RIPv1 Limitations RIP 1 Li it ti RIPv1 – a classful routing protocol –Subnet mask are not sent in updates Subnet –Summarizes networks at major network boundaries –RIPv1 cannot support... Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 20 Configuring RIPv2 Enabling and Verifying RIPv2 Configuring RIP on a Cisco router –By default it is running RIPv1 –Even though the router only sends RIPv1 messages, it can interpret both RIPv1 and RIPv2 messages messages –A RIPv1 router will just ignore the RIPv2 fields in the route entry RIPv1 ITE PC v4.0 Chapter 1 RIPv2 © 20 07. .. command -RIPv2 ignores RIPv1 RIPv2 updates To verify RIPv2 is configured use the show ip protocols command ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 22 Comparing RIP v1 and v2 RIP v2 send and receive v2 RIP v1 send v1 but can receive both v1 and v2 RIP network is broken I can only send l d version 1 Version 2 Version 1 Yes I can take version 1 or 2 ITE PC v4.0 Chapter . network 172 .30.0.0/16: – 172 .30.100.0/24 (FastEthernet 0/0) 172 .30.100.0/24 (FastEthernet 0/0) –1 72 .30.110.0/24 (Loopback 0) –1 72 .30.200.16/28 (Loopback 1) 172 30 200 32/28 (L b k 2) – 172 . 30 . 200 . 32/28 . and R3 have had the 172 .30.0.0/16 network subnetted into /24 subnets subnets . –Four of these /24 subnets are assigned: – two to R1 ( 172 .30.1.0/24 and ( 172 .30.2.0/24) –two to R3 ( 172 .30.100.0/24. RIPv2 Routing Protocols and Concepts – Chapter 7 © 20 07 Cisco Systems, Inc. All rights reserved. Cisco Public ITE PC v4.0 Chapter 1 1 Objectives  En cou nt e r