Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 7 RIP version 2. RIPv1 Limitations RIPv1: Topology Limitations RIPv1: Discontiguous Networks RIPv1: No VLSM Support RIPv1: No CIDR Support.

Similar presentations


Presentation on theme: "Chapter 7 RIP version 2. RIPv1 Limitations RIPv1: Topology Limitations RIPv1: Discontiguous Networks RIPv1: No VLSM Support RIPv1: No CIDR Support."— Presentation transcript:

1 Chapter 7 RIP version 2

2 RIPv1 Limitations RIPv1: Topology Limitations RIPv1: Discontiguous Networks RIPv1: No VLSM Support RIPv1: No CIDR Support

3 3 RIPv1: Distance Vector, Classess Routing Protocol RIP Version 2 (RIPv2) is defined in RFC RIPv2 is the first classless routing protocol discussed in this book. RIPv2 has lost popularity when compared to other routing protocols such as EIGRP, OSPF and IS-IS. RIPv2, it is ideal for explaining the differences between a classful routing protocol (RIPv1) and a classless routing protocol (RIPv2).

4 4 RIPv1 and RIPv2 RIPv2 is actually an enhancement of RIPv1’s features and extensions rather than an entirely new protocol.  Next-hop addresses included in the routing updates  Use of multicast addresses in sending updates  Authentication option available Both versions of RIP share the following features and limitations:  Use of hold-down and other timers to help prevent routing loops  Use of split horizon and 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 hops, with the hop count of 16 signifying an unreachable network

5 5 In a discontiguous network, a classful major network address, such as /16, is separated by one or more other major networks /16 is divided by the networks:  /30  /30 Classful routing protocols do not include enough routing information to route properly for discontiguous networks. RIPv1 Limitations /16

6 6 R2: static summary route to the /16 network.  Redistribution - Inject static route(s) into routing protocol updates. Summary Route /16 R2(config)# ip route null0 R2(config-router)#redistribute static

7 7 R1 and R3 contain VLSM networks. Both R1 and R3 are configured with /24 subnets of the /16 network. R3: /24 subnetted again, using the first 4 bits for subnets and the last 4 for hosts.  /28 and /28 VLSM /16

8 8 VLSM R3: /24 subnetted again, using the first 4 bits for subnets and the last 4 for hosts /28 and /28

9 9 Loopback interface  Software-only interface  Used to emulate an interface.  Can be assigned an IP address.  Specific purposes with some routing protocols such as OSPF (later) A loopback interface can be:  pinged  subnet advertised in routing updates. Ideal for simulating multiple networks attached to the same router. Loopback Interfaces /16

10 10 RIPv1 Topology Limitations RIPv1 configuration for all three routers R1(config)# router rip R1(config-router)# network R1(config-router)# network R2(config)# ip route null0 R2(config)# router rip R2(config-router)# redistribute static R2(config-router)# network R2(config-router)# network R3(config)# router rip R3(config-router)# network R3(config-router)# network

11 11 Static Routes and Null Interfaces CIDR allows route aggregation.  A single high-level route entry with a subnet mask less than the classful mask can be used to represent many lowerlevel routes. This results in fewer entries in the routing table. The static route on R2 is using a /16 mask to summarize all 256 networks ranging from /24 to /24. For Lab purposes:  The static summary route /16 does not actually exist.  To simulate this static route, we will use a null interface as the exit interface.  You do not need to enter commands to create or configure the null interface.  It is always up but does not forward or receive traffic.  Traffic sent to the null interface is discarded. R2(config)# ip route Null0

12 12 Route Redistribution Redistribution involves taking the routes from one routing source and sending those routes to another routing source. Routes can only be redistributed into a dynamic routing protocol.  Dynamic routing protocol to a different dynamic routing protocol.  Static routes to a dynamic routing protocol.  Directly connected networks to a dynamic routing protocol. Want R2 to redistribute our static route ( /16) by importing the route into RIPv1 and then sending it to R1 and R3 using the RIPv1 process. R2(config)# ip route null0 R2(config)# router rip R2(config-router)# redistribute static Is static route being sent via RIPv1 with other RIPv1 routes?

13 13 Verifying and Testing Connectivity Whenever R2 pings any of the subnets on R1 or R3, only about 50 percent of the pings are successful. R2# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !U!.! Success rate is 60 percent (3/5), round-trip min/avg/max = 28/29/32 ms R2# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !U!.! Success rate is 60 percent (3/5), round-trip min/avg/max = 28/28/28 ms R2#

14 14 Verifying and Testing Connectivity R1 is able to ping but is unsuccessful when attempting to ping the interface on R3. R1# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5),round-trip min/avg/max = 28/28/28 ms R1# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:..... Success rate is 0 percent (0/5) R1# X

15 15 Verifying and Testing Connectivity R3 is able to ping but is unsuccessful when attempting to ping the interface on R1. As you can see, there is an obvious problem when trying to communicate with the discontiguous subnets. R3# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5),round-trip min/avg/max = 28/28/28 ms R3# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:..... Success rate is 0 percent (0/5) R3# X

16 16 RIPv1 on both Routers R1 and R3 will summarize their subnets to the classful major network address of when sending routing updates to R2. RIPv1: Discontiguous Networks

17 17 Examining the Routing Tables R2 has two equal-cost routes to the /16 network.  R1 and R3 are sending R2 a RIPv1 update for the network with a metric of 1 hop. R2’s routing table only contains the major classful network address of and adds the Class B subnet mask of /16. R2# show ip route R /16 [120/1] via , 00:00:09, Serial0/0/0 [120/1] via , 00:00:11, Serial0/0/ /30 is subnetted, 2 subnets C is directly connected, Serial0/0/1 C is directly connected, Serial0/0/ /16 is subnetted, 1 subnets C is directly connected, FastEthernet0/0 S /16 is directly connected, Null0

18 18 debug ip rip R2 is receiving two equal-cost routes with a metric of 1 hop:  one route on Serial 0/0/0 from R1 and  the other route on Serial 0/0/1 from R3. Also notice that the subnet mask is not included with the network address in the update. R2# debug ip rip RIP: received v1 update from on Serial0/0/ in 1 hops RIP: received v1 update from on Serial0/0/ in 1 hops RIP: sending v1 update to via Serial0/0/0 ( ) RIP: build update entries network metric 1 subnet metric 1 RIP: sending v1 update to via Serial0/0/1 ( ) RIP: build update entries network metric 1 subnet metric 1

19 19 show ip route R1 has its own routes:  /24  /24. R1 does not send R2 those subnets. R1 and R3 are boundary routers only sending the summarized Result, R2 only knows about the /16 classful network and is unaware of any subnets. R1# show ip route /24 is subnetted, 2 subnets C is directly connected, Loopback0 C is directly connected, FastEthernet0/ /30 is subnetted, 2 subnets R [120/1] via , 00:00:16,Serial0/0/0 C is directly connected, Serial0/0/0 R /8 [120/1] via , 00:00:16, Serial0/0/0 R1#

20 20 How Classful Routing Protocols Determine Subnet Masks Apply classful default mask of /16

21 21 How Classful Routing Protocols Determine Subnet Masks Apply classful default mask of /

22 22 How Classful Routing Protocols Determine Subnet Masks VLSM issues: will discuss next

23 23 RIPv1: No VLSM Support Because RIPv1 does not send the subnet mask in routing updates, it cannot support VLSM. The R3 router is configured with the following VLSM subnets, all of which are members of the Class B network /16:  /24 (FastEthernet 0/0)  /24 (Loopback 0)  /28 (Loopback 1)  /28 (Loopback 2)

24 24 RIPv1: No CIDR Support We see the static route, let’s see if it is be sent in RIPv1 updates with the other RIPv1 routes… R2(config)# ip route null0 R2(config)# router rip R2(config-router)# redistribute static R2(config-router)# network R2(config-router)# network R2(config-router)# end R2# show ip route R /16 [120/1] via , 00:00:09, Serial0/0/0 [120/1] via , 00:00:11, Serial0/0/ /30 is subnetted, 2 subnets C is directly connected, Serial0/0/1 C is directly connected, Serial0/0/ /16 is subnetted, 1 subnets C is directly connected, FastEthernet0/0 S /16 is directly connected, Null0

25 25 R1 Routing Table Notice that R1 is not receiving this /16 route in its RIP updates from R2 R1# show ip route /24 is subnetted, 2 subnets C is directly connected, FastEthernet0/1 C is directly connected, FastEthernet0/ /30 is subnetted, 2 subnets R [120/1] via , 00:00:16,Serial0/0/0 C is directly connected, Serial0/0/0 R /8 [120/1] via , 00:00:16, Serial0/0/0

26 26 debug ip rip R2 is not including the /16 route in its RIPv1 updates to either R1 or R3. R2# debug ip rip RIP: received v1 update from on Serial0/0/ in 1 hops RIP: received v1 update from on Serial0/0/ in 1 hops RIP: sending v1 update to via Serial0/0/0 ( ) RIP: build update entries network metric 1 subnet metric 1 RIP: sending v1 update to via Serial0/0/1 ( ) RIP: build update entries network metric 1 subnet metric 1

27 27 RIPv1: No CIDR Support The static route has a /16 mask. This is fewer bits than the classful Class C mask of /24. RIPv1 and other classful routing protocols cannot support CIDR routes that are summarized routes with a smaller subnet mask than the classful mask of the route. RIPv1 ignores these supernets in the routing table and does not include them in updates to other routers. This is because the receiving router would only be able to apply the larger /24 classful mask to the update and not the shorter /16 mask. Note:  If the static route were configured with a /24 mask or greater, this route would be included in the RIP updates.  The receiving routers would apply the classful /24 mask to this update. R2(config)# ip route null0 R2(config)# router rip R2(config-router)# redistribute static

28 Configuring RIPv2 Enabling and Verifying RIPv2 Auto-Summary and RIPv2 Disabling Auto-Summary in RIPv2 Verifying RIPv2 Updates

29 29 Configuring RIPv2 Configuring RIPv2 is similar to configuring RIPv1, with the addition of a single RIP command, version 2. Although RIPv2 uses the same basic configuration commands as RIPv1, the results of using RIPv2 are different, allowing both CIDR and VLSM to be used in the network.

30 30 Enabling and Verifying RIPv2 Default RIPv1: When configuring RIP  Router only sends RIPv1 messages, it can process both RIPv1 and RIPv2 messages.  Ignore the RIPv2 fields in the route entry. RIPv2 will ignore RIPv1 updates. R2# show ip protocols Default version control: send version 1, receive any version Interface Send Recv Triggered RIP Key-chain Serial0/0/ Serial0/0/ Automatic network summarization is in effect

31 31 Enabling and Verifying RIPv2 version 2 command is used to modify RIP to use Version 2. This command should be configured on all routers in the routing domain. R1(config)# router rip R1(config-router)# version 2 R2(config)# router rip R2(config-router)# version 2 R3(config)# router rip R3(config-router)# version 2

32 32 Enabling and Verifying RIPv2 R2# show ip protocols Routing Protocol is “rip” Sending updates every 30 seconds, next due in 1 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: static, rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain Serial0/0/0 2 2 Serial0/0/1 2 2 Automatic network summarization is in effect

33 33 Restoring RIP to Version 1 Default behavior of RIPv1 can be restored by using either the (slightly different behaviors in sending and receiving):  version 1 command  no version command If done, should be configured on all routers. R1(config)# router rip R1(config-router)# version 1 !or R1(config)# router rip R1(config-router)# no version

34 34 Auto-Summary and RIPv2 You still see the summarized /16 route with the same two equal-cost paths. R2# show ip route R /16 [120/1] via , 00:00:28, Serial0/0/0 [120/1] via , 00:00:18, Serial0/0/ /30 is subnetted, 2 subnets C is directly connected, Serial0/0/1 C is directly connected, Serial0/0/ /16 is subnetted, 1 subnets C is directly connected, FastEthernet0/0 S /16 is directly connected, Null0

35 35 Auto-Summary and RIPv2 Routers R1 and R3 still do not include the subnets of the other router. The only difference so far between RIPv1 and RIPV2 is that R1 and R3 each have a route to /16. This route was the (CIDR) static route configured on R2 and redistributed by RIP. What’s happening? R1# show ip route /24 is subnetted, 2 subnets C is directly connected, Loopback0 C is directly connected, FastEthernet0/ /30 is subnetted, 2 subnets R [120/1] via , 00:00:04,Serial0/0/0 C is directly connected, Serial0/0/0 R /8 [120/1] via , 00:00:04, Serial0/0/0 R /16 [120/1] via , 00:00:04, Serial0/0/0

36 36 Auto-Summary and RIPv2 Notice that RIPv2 is sending both the network address and subnet mask. Notice that the route sent is the summarized classful network address, /16  not the individual /24 and /24 subnets. R1# debug ip rip RIP: sending v2 update to via Serial0/0/0 ( ) RIP: build update entries /16 via , metric 1, tag 0 RIP: received v2 update from on Serial0/0/ /8 via in 1 hops /16 via in 1 hops /30 via in 1 hops

37 37 Auto-Summary and RIPv2 By default, RIPv2 automatically summarizes networks at major network boundaries, just like RIPv1. Both R1 and R3 routers are still summarizing their subnets to the Class B address of when sending updates out their interfaces on the and networks, respectively. R1# show ip protocols Routing Protocol is “rip” Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain FastEthernet0/0 2 2 FastEthernet0/1 2 2 Serial0/1/0 2 2 Automatic network summarization is in effect

38 38 Disabling Auto-summary in RIPv2 To modify the default RIPv2 behavior of automatic summarization, use the no auto-summary command R2(config)# router rip R2(config-router)# no auto-summary R3(config)# router rip R3(config-router)# no auto-summary R1(config)# router rip R1(config-router)# no auto-summary R1# show ip protocols Automatic network summarization is not in effect

39 39 Verifying RIPv2 Updates The routing table for R2 now contains the individual subnets for /16. Notice that a single summary route with two equal-cost paths no longer exists. Each subnet and mask has its own specific entry, along with the exit interface and next-hop address to reach that subnet. R2# show ip route /16 is variably subnetted, 6 subnets, 2 masks R /28 [120/1] via , 00:00:09, Serial0/0/1 R /28 [120/1] via , 00:00:09, Serial0/0/1 R /24 [120/1] via , 00:00:03, Serial0/0/0 R /24 [120/1] via , 00:00:03, Serial0/0/0 R /24 [120/1] via , 00:00:09, Serial0/0/1 R /24 [120/1] via , 00:00:09, Serial0/0/ /30 is subnetted, 2 subnets C is directly connected, Serial0/0/1 C is directly connected, Serial0/0/ /16 is subnetted, 1 subnets C is directly connected, FastEthernet0/0 S /16 is directly connected, Null0

40 40 Verifying RIPv2 Updates Fully converged routing tables. R1# show ip route /16 is variably subnetted, 6 subnets, 2 masks R /28 [120/2] via , 00:00:01, Serial0/0/0 R /28 [120/2] via , 00:00:01, Serial0/0/0 C /24 is directly connected, Loopback0 C /24 is directly connected, FastEthernet0/0 R /24 [120/2] via , 00:00:01, Serial0/0/0 R /24 [120/2] via , 00:00:01, Serial0/0/ /30 is subnetted, 2 subnets R [120/1] via , 00:00:02, Serial0/0/0 C is directly connected, Serial0/0/ /16 is subnetted, 1 subnets R [120/1] via , 00:00:02, Serial0/0/0 R /16 [120/1] via , 00:00:02, Serial0/0/0

41 41 Verifying RIPv2 Updates Fully converged routing tables. R3# show ip route /16 is variably subnetted, 6 subnets, 2 masks C /28 is directly connected, Loopback2 C /28 is directly connected, Loopback1 R /24 [120/2] via , 00:00:01, Serial0/0/1 R /24 [120/2] via , 00:00:01, Serial0/0/1 C /24 is directly connected, FastEthernet0/0 C /24 is directly connected, Loopback /30 is subnetted, 2 subnets C is directly connected, Serial0/0/1 R [120/1] via , 00:00:02, Serial0/0/ /16 is subnetted, 1 subnets R [120/1] via , 00:00:02, Serial0/0/1 R /16 [120/1] via , 00:00:02, Serial0/0/1

42 42 Verifying RIPv2 Updates R2# debug ip rip RIP: received v2 update from on Serial0/0/ /24 via in 1 hops /24 via in 1 hops /28 via in 1 hops /28 via in 1 hops RIP: sending v2 update to via Serial0/0/0 ( ) RIP: build update entries /16 via , metric 1, tag /24 via , metric 2, tag /24 via , metric 2, tag /28 via , metric 2, tag /28 via , metric 2, tag /16 via , metric 1, tag /30 via , metric 1, tag 0 Sending and receiving routing updates, which are individual routes with their subnet mask instead of a single summary route with the classful mask.

43 43 Verifying RIPv2 Updates Notice also that the updates are sent using the multicast address RIPv1 sends updates as a broadcast In general multicast updates:  Take up less bandwidth on the network.  Require less processing by devices that are not RIP enabled. R2# debug ip rip RIP: sending v2 update to via Serial0/0/0 ( )

44 VLSM and CIDR RIPv2 and VLSM RIPv2 and CIDR

45 45 RIPv2 and VLSM With RIPv2, R3 can now include all the subnets in its routing updates to R4 This is because RIPv2 can include the proper subnet mask with the network address in the update. Added R4 for purposes of this discussion

46 46 RIPv2 and VLSM R3# debug ip rip RIP: sending v2 update to via FastEthernet0/0 ( ) RIP: build update entries /16 via , metric 2, tag /24 via , metric 3, tag /24 via , metric 3, tag /24 via , metric 1, tag /28 via , metric 1, tag /28 via , metric 1, tag /16 via , metric 2, tag /30 via , metric 2, tag /30 via , metric 1, tag 0

47 Verifying and Troubleshooting RIPv2 Verification and Troubleshooting Commands Common RIPv2 Issues Authentication

48 48 show ip route Command First command to use to check for network convergence. Important to look for the routes that you expect to be in the routing table as well as for those that should not be in the routing table. R1# show ip route /16 is variably subnetted, 6 subnets, 2 masks R /28 [120/2] via , 00:00:01, Serial0/0/0 R /28 [120/2] via , 00:00:01, Serial0/0/0 C /24 is directly connected, Loopback0 C /24 is directly connected, FastEthernet0/0 R /24 [120/2] via , 00:00:01, Serial0/0/0 R /24 [120/2] via , 00:00:01, Serial0/0/ /30 is subnetted, 2 subnets R [120/1] via , 00:00:02, Serial0/0/0 C is directly connected, Serial0/0/ /16 is subnetted, 1 subnets R [120/1] via , 00:00:02, Serial0/0/0 R /16 [120/1] via , 00:00:02, Serial0/0/0

49 49 show ip interface brief Command If a network is missing from the routing table, it is often because an interface is down or incorrectly configured. The show ip interface brief command quickly verifies the status of all interfaces. R1# show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/ YES NVRAM up up FastEthernet0/ YES NVRAM up up Serial0/0/ YES NVRAM up up Serial0/0/1 unassigned YES NVRAM down down

50 50 show ip protocols Command The show ip protocols command verifies several critical items, including whether RIP is enabled, the version of RIP, the status of automatic summarization, and the networks that were included in the network statements. R1# show ip protocols Routing Protocol is “rip” Sending updates every 30 seconds, next due in 29 seconds Invalid after 180 seconds, hold down 180, flushed after 240 Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Redistributing: rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain FastEthernet0/0 2 2 FastEthernet0/1 2 2 Serial0/0/0 2 2 Automatic network summarization is not in effect Maximum path: 4 Routing for Networks: Routing Information Sources: Gateway Distance Last Update :00:18 Distance: (default is 120)

51 51 debug ip rip Command debug ip rip is an excellent command to use to examine the contents of the routing updates that are sent and received by a router. There can be times when a route is received by a router but is not added to the routing table. One reason for this could be that a static route is also configured for the same advertised network. R2# debug ip rip RIP: received v2 update from on Serial0/0/ /24 via in 1 hops /24 via in 1 hops /28 via in 1 hops /28 via in 1 hops RIP: sending v2 update to via Serial0/0/0 ( ) RIP: build update entries /16 via , metric 1, tag /24 via , metric 2, tag /24 via , metric 2, tag /28 via , metric 2, tag /28 via , metric 2, tag /16 via , metric 1, tag /30 via , metric 1, tag 0

52 52 ping Command An easy way to verify round-trip connectivity is with the ping command R2# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms R2# ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms

53 53 show running-config Command R1# show running-config ! hostname R1 ! interface FastEthernet0/0 ip address ! interface FastEthernet0/1 ip address ! interface Serial0/0/0 ip address clock rate ! router rip version 2 network network no auto-summary !

54 54 Common RIPv2 Issues Version:  Although RIPv1 and RIPv2 can be made compatible with additional commands beyond the scope of this course, RIPv1 does not support discontiguous subnets, VLSM, or CIDR supernet routes. network statements:  Another source of problems might be incorrectly configured or missing network statements configured with the network command.  Remember, the network command does two things: 1.It enables the routing protocol to send and receive updates on any local interfaces that belong to that network. 2.It includes the configured network in its routing updates to its neighboring routers.  A missing or incorrect network statement will result in missed routing updates and routing updates not being sent or received on an interface. Automatic summarization:  If there is a need or expectation for sending specific subnets and not just summarized routes, make sure that automatic summarization has been disabled with the no auto-summary command.

55 55 Authentication It is good practice to authenticate routing information. RIPv2, EIGRP, OSPF, IS-IS, and Border Gateway Protocol (BGP) can be configured to encrypt and authenticate routing information.  Hides the content of the routing information  Routers will only accept routing information from other routers that have been configured with the same password or authentication information. Covered in CIS 83.


Download ppt "Chapter 7 RIP version 2. RIPv1 Limitations RIPv1: Topology Limitations RIPv1: Discontiguous Networks RIPv1: No VLSM Support RIPv1: No CIDR Support."

Similar presentations


Ads by Google