Tài liệu EIGRP Troubleshooting pptx

1-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. Lab 12.2.1.1 EIGRP Troubleshooting F0/0 192.168.0.1/24 S0/1 192.168.112.1/24S0/0 192.168.64.1/30 S0/0 192.168.64.2/30 S0/1 192.168.112.2/24 Fa0/0 192.168.72.1/24 Fa0/0 192.168.120.1/24 SanJose1 West asman East asman Objective Utilize a systematic approach to troubleshoot a simple network problem. Scenario You have been asked to check out the Westasman, SanJose1 and Eastasman routers. It has been determined that workstations connected to the Westasman router cannot communicate with users on the SanJose1 or Eastasman routers. The workstations on the Eastasman router cannot communicate with either the Westasman or SanJose1 workstations. Lab Tasks Build the network according to the diagram above and load the appropriate ‘broken’ configuration files to each router. Save the configurations and reload each router. Clock rates have been applied to all serial interfaces. Step 1 Define your problem. Users report that they are unable to communicate with workstations on remote networks. Users on the same network are able to communicate with each other. Step 2 Gather the Facts. 2-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. Based on the current information you have, all the evidence points to a WAN link failure. You then login to the routers to gather more information about the problem. Issue the following commands to narrow down your possibilities. The first thing to check is your connections. SanJose1#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.0.1 YES manual up up Serial0/0 192.168.112.1 YES manual up up Serial0/1 192.168.64.2 YES manual up up Eastasman#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.120.1 YES manual up up Serial0/0 192.168.112.2 YES manual up up BRI0/0 unassigned YES unset administratively down down BRI0/0:1 unassigned YES unset administratively down down BRI0/0:2 unassigned YES unset administratively down down FastEthernet0/1 unassigned YES unset administratively down down Serial0/1 unassigned YES unset administratively down down Westasman#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.72.1 YES manual up up Serial0/0 192.168.64.1 YES manual up up BRI0/0 unassigned YES unset administratively down down BRI0/0:1 unassigned YES unset administratively down down BRI0/0:2 unassigned YES unset administratively down down Serial0/1 unassigned YES unset administratively down down Then check the routing table to see if you have the appropriate routes. Note – in a very large network you can enter a network number to limit the display. SanJose1#show 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, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set 192.168.64.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.64.0/30 is directly connected, Serial0/1 C 192.168.64.1/32 is directly connected, Serial0/1 192.168.112.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.112.0/24 is directly connected, Serial0/0 C 192.168.112.2/32 is directly connected, Serial0/0 C 192.168.0.0/24 is directly connected, FastEthernet0/0 Eastasman#show 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, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set C 192.168.120.0/24 is directly connected, FastEthernet0/0 192.168.112.0/24 is variably subnetted, 2 subnets, 2 masks 3-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. C 192.168.112.0/24 is directly connected, Serial0/0 C 192.168.112.1/32 is directly connected, Serial0/0 Westasman#show 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, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set C 192.168.72.0/24 is directly connected, FastEthernet0/0 192.168.64.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.64.0/30 is directly connected, Serial0/0 C 192.168.64.2/32 is directly connected, Serial0/0 EIGRP log-neighbor-changes is the best tool you have to diagnose un- stable neighbor relationships. You may want to enable it on every router in your network. The uptime value from show ip eigrp neighbors will tell you the last time a neighbor relationship was reset (bounced), but not how often or why. With log-neighbor-changes on and logging buffered, you keep not only a history of when neighbors have been reset, but the reason why. Logging buffered is also recommended because logging to a syslog server is dependent on the network. For example, if the neighbor bouncing is between the router losing neighbors and the syslog server, the messages could be lost. It may be prudent to keep these types of messages locally on the router. It may also be useful to increase the size of the buffer log in order to capture a greater duration of error messages. You would hate to lose the EIGRP neighbor messages because of flapping links filling the buffer log. If your routers have enough memory to hold the log file, change the buffer log size us- ing the command logging buffered {value} in configuration mode. SanJose1(config)#router eigrp 123 SanJose1(config-router)#eigrp log-neighbor-changes SanJose1(config-router)#exit SanJose1(config)#logging buffered 4096 02:09:15: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.64.1 (Serial0/1) is up: new adjacency 02:09:16: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.64.1 (Serial0/1) is down: holding time expired 02:09:16: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.112.2 (Serial0/0) is up: new adjacency 02:09:17: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.112.2 (Serial0/0) is down: holding time expired 02:09:24: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.64.1 (Serial0/1) is up: new adjacency 02:09:25: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.64.1 (Serial0/1) is down: holding time expired 02:09:25: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.112.2 (Serial0/0) is up: new adjacency 02:09:26: %DUAL-5-NBRCHANGE: IP-EIGRP 123: Neighbor 192.168.112.2 (Serial0/0) is down: holding time expired Step 3 Consider the possibilities. Use the information you have and your knowledge of Cisco products to isolate the problem. 4-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. Neighbor relationships are flapping. Possible configuration error within the rout- ing protocol. Check routing information. Step 4 Create an action plan. Confirm the configuration of the EIGRP routing protocol. Change configurations as necessary. Step 5 Implement the action plan. Confirm the configuration of eigrp 123 on the routers. Note – the following command can be used to parse the output of the running configuration. SanJose1#show run | begin router eigrp router eigrp 123 network 192.168.0.0 network 192.168.64.0 0.0.0.3 network 192.168.112.0 no auto-summary eigrp log-neighbor-changes ! ip classless no ip http server ! banner motd ^CCLab 12-1^C ! line con 0 password 7 030752180500 login transport input none line aux 0 line vty 0 4 password 7 070C285F4D06 login ! no scheduler allocate end Eastasman#show run | begin router eigrp router eigrp 123 network 192.168.112.0 network 192.168.120.0 no auto-summary ! ip classless no ip http server ! banner motd ^CCLab 12-1^C ! line con 0 password 7 110A1016141D login transport input none line aux 0 line vty 0 4 password 7 14141B180F0B login ! ! 5-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. no scheduler allocate end Westasman#show run | begin router eigrp router eigrp 123 network 192.168.64.0 0.0.0.3 network 192.168.72.0 no auto-summary ! ip classless no ip http server ! banner motd ^CCLab 12-1^C ! line con 0 exec-timeout 0 0 password cisco login transport input none line aux 0 line vty 0 4 password cisco login ! ! no scheduler allocate end Everything looks fine here. Now check the hello-interval and hold-time on each interface. Note – on core routers with long configurations, parsing output will always help to reduce the information displayed. SanJose1#show run interface s0/0 Building configuration Current configuration : 179 bytes ! interface Serial0/0 ip address 192.168.112.1 255.255.255.0 ip hello-interval eigrp 123 10 ip hold-time eigrp 123 1 encapsulation ppp no ip mroute-cache no fair-queue end SanJose1#show run interface s0/1 Building configuration Current configuration : 145 bytes ! interface Serial0/1 ip address 192.168.64.2 255.255.255.252 ip hello-interval eigrp 123 10 ip hold-time eigrp 123 1 encapsulation ppp end Westasman#show run interface s0/0 Building configuration Current configuration: ! interface Serial0/0 ip address 192.168.64.1 255.255.255.252 6-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. no ip directed-broadcast ip hello-interval eigrp 123 180 ip hold-time eigrp 123 540 encapsulation ppp no ip mroute-cache no fair-queue clockrate 56000 end Eastasman#show run interface s0/0 Building configuration Current configuration: ! interface Serial0/0 ip address 192.168.112.2 255.255.255.0 no ip directed-broadcast ip hello-interval eigrp 123 180 ip hold-time eigrp 123 540 encapsulation ppp no ip mroute-cache no fair-queue clockrate 56000 end Based on your knowledge of EIGRP, you know that the hello-interval and the hold-time for the SanJose1 router is incorrectly configured. A general rule is to set the hello-interval to 180 seconds on slow WAN links and the hold-time to 3 times the hello-interval, which would be 540 seconds. Issue the following commands to remedy the situation. SanJose1(config)#interface s0/0 SanJose1(config-if)#ip hello-interval eigrp 123 180 SanJose1(config-if)#ip hold-time eigrp 123 540 SanJose1(config)#interface s0/1 SanJose1(config-if)#ip hello-interval eigrp 123 180 SanJose1(config-if)#ip hold-time eigrp 123 540 Step 6 Observe the Results of the action plan. Login to each router. Check if the routing tables are being populated properly. Also, perform an extended ping from end to end. Issue the show ip route command: SanJose1#show 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, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set D 192.168.72.0/24 [90/20514560] via 192.168.64.1, 00:01:00, Serial0/1 D 192.168.120.0/24 [90/20514560] via 192.168.112.2, 00:00:18, Serial0/0 192.168.64.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.64.0/30 is directly connected, Serial0/1 C 192.168.64.1/32 is directly connected, Serial0/1 192.168.112.0/24 is variably subnetted, 2 subnets, 2 masks 7-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. C 192.168.112.0/24 is directly connected, Serial0/0 C 192.168.112.2/32 is directly connected, Serial0/0 C 192.168.0.0/24 is directly connected, FastEthernet0/0 Westasman#show 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, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set C 192.168.72.0/24 is directly connected, FastEthernet0/0 D 192.168.120.0/24 [90/21026560] via 192.168.64.2, 00:01:01, Serial0/0 192.168.64.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.64.0/30 is directly connected, Serial0/0 C 192.168.64.2/32 is directly connected, Serial0/0 192.168.112.0/24 is variably subnetted, 2 subnets, 2 masks D 192.168.112.0/24 [90/21024000] via 192.168.64.2, 00:02:31, Serial0/0 D 192.168.112.2/32 [90/21024000] via 192.168.64.2, 00:02:31, Serial0/0 D 192.168.0.0/24 [90/20514560] via 192.168.64.2, 00:02:31, Serial0/0 Eastasman#show 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, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set D 192.168.72.0/24 [90/21026560] via 192.168.112.1, 00:01:35, Serial0/0 C 192.168.120.0/24 is directly connected, FastEthernet0/0 192.168.64.0/24 is variably subnetted, 2 subnets, 2 masks D 192.168.64.0/30 [90/21024000] via 192.168.112.1, 00:01:35, Serial0/0 D 192.168.64.1/32 [90/21024000] via 192.168.112.1, 00:01:35, Serial0/0 192.168.112.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.112.0/24 is directly connected, Serial0/0 C 192.168.112.1/32 is directly connected, Serial0/0 D 192.168.0.0/24 [90/20514560] via 192.168.112.1, 00:01:35, Serial0/0 Issue an extended ping command to test end-to-end connectivity: Eastasman#ping Protocol [ip]: ip Target IP address: 192.168.72.1 Repeat count [5]: Datagram size [100]: Timeout in seconds [2]: Extended commands [n]: y Source address or interface: 192.168.120.1 Type of service [0]: Set DF bit in IP header? [no]: Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.72.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 72/77/96 ms 8-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. Step 7 Document your work. . 1-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 12.2.1.1 Copyright  2001, Cisco Systems, Inc. Lab 12.2.1.1 EIGRP Troubleshooting F0/0 192.168.0.1/24 S0/1. | begin router eigrp router eigrp 123 network 192.168.0.0 network 192.168.64.0 0.0.0.3 network 192.168.112.0 no auto-summary eigrp log-neighbor-changes