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 [...]... v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 32 Verifying T V if i & Troubleshooting RIPv2 bl h ti RIP 2 Reasons why it’s good to authenticate routing information y g g -Prevent the possibility of accepting invalid routing updates -Contents of routing updates are encrypted g p yp Types of routing protocols that can use authentication -RIPv2 RIPv2 -EIGRP -OSPF OSPF -IS-IS -BGP... v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 29 VLSM & CIDR To verify that supernets are being sent and received use the following commands -Show ip route -Debug ip rip Debug ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 30 Verifying & Troubleshooting RIPv2 Basic Troubleshooting steps -Check the status of all links Check -Check cabling -Check... 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, Inc All rights... R3 router is configured with VLSM subnets, subnets all of which are members of the class B network 172 .30.0.0/16: – 172 .30.100.0/24 (FastEthernet 0/0) 172 .30.100.0/24 – 172 .30.110.0/24 (Loopback 0) – 172 .30.200.16/28 (Loopback 1) – 172 .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... which subnets 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... 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 the 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... 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 As you will see R2 installs both paths in the 172 .30.0.0/16 see, routing table ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved... the RIPv2 fields in the route entry RIPv1 ITE PC v4.0 Chapter 1 RIPv2 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 21 Configuring RIPv2 Configuring RIPv2 on a Cisco router -Requires using the version 2 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... Yes I can take version 1 or 2 ITE PC v4.0 Chapter 1 No No I can not take version 1 I can only send version 2 © 20 07 Cisco Systems, Inc All rights reserved Cisco Public 23 POP Quiz How do you make the RIPv2 back to the default “send 1” and receive 1 or 2”? - Hint: Gad(config-router)#version 1 is not the answer Version 2 Version 1 ITE PC v4.0 Chapter 1 © 20 07 Cisco Systems, Inc All rights reserved Cisco... 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 the other route on Serial 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 . network 172 .30.0.0/16: – 172 .30.100.0/24 (FastEthernet 0/0) 172 .30.100.0/24 (FastEthernet 0/0) – 172 .30.110.0/24 (Loopback 0) – 172 .30.200.16/28 (Loopback 1) 172 30 200 32/28 (L b k 2) – 172 . 30 . 200 . 32/28 . 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) on l y i nc l u d e 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