Tài liệu Troubleshooting TCP/IP – Show and Debug pptx

1-1 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. Lab 4.6.3: Troubleshooting TCP/IP – Show and Debug SanJose1 SanJose2 #2#1 S0/0 S0/0 192.168.1.10 192.168.2.10 Objective There are many commands that are useful for troubleshooting TCP/IP. It is likely that you have used some of them in earlier classes. In this exercise you will look at some options, but we will save most commands for later chapters when you are looking at specific protocols. This lab covers: • show commands • debug commands Warning: The debug command because of its heavy use of CPU cycles can be devastating to a production router’s performance. It is possible that a command such as debug IP packet running, during a moderate to heavy traffic period could literally consume all CPU cycles and effectively stop routing, resulting in discarded frames. This discussion is included primarily as a tool to help you visualize how and why certain network processes occur. We will also look at options that can reduce the impact of the debug commands. Scenario You have been asked to consult on a small network and offer suggestions on how performance might be improved. You are gathering information about the network. Note: The configuration file used for this lab will be used for other module 4 labs, so please do not change any configuration settings. The configuration contains several components for testing purposes and is not intended to represent a good production configuration. 2-2 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. If the lab is done in pairs, each person can run the lab steps each may get slightly different results. It might be beneficial to coordinate your efforts and compare results. Step 1 Cable the lab as shown in the diagram. Load the configuration files Lab4-6-3-SanJose1Config.txt and Lab4-6-3- SanJose2Config.txt into the appropriate routers. Configure the workstations as follows (same as the last lab): Host #1 Host #2 IP Address: 192.168.1.10 IP Address: 192.168.2.10 Subnet mask: 255.255.255.0 Subnet mask: 255.255.255.0 Default Gateway: 192.168.1.1 Default Gateway: 192.168.2.1 Step 2 The show ip access-list and clear ip access-list counters commands On either router type show ip access-list and look over the results. You may notice a message indicating matches after some entries like those highlighted below: SanJose1#show ip access-list Standard IP access list 50 deny 192.168.60.0, wildcard bits 0.0.0.255 deny 192.168.70.0, wildcard bits 0.0.0.255 deny 192.168.80.64, wildcard bits 0.0.0.31 permit any Extended IP access list 100 deny tcp any 192.168.90.0 0.0.0.255 eq www deny tcp any 192.168.90.0 0.0.0.255 eq ftp deny tcp any 192.168.91.0 0.0.0.255 eq www deny tcp any 192.168.91.0 0.0.0.255 eq ftp deny icmp any host 192.168.60.1 permit ip any any (8571 matches) Extended IP access list protect_acctg_servers deny tcp 192.168.60.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.70.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.80.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.90.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.91.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www permit ip any any (44294 matches) SanJose1# These “matches” messages indicate the results of the access list since the last time the counters were cleared or the router rebooted. The clear ip access-list counters command can be used to clear the counters. Try it. You may find that like the following example a routing update or some other activity immediately started the counters again. SanJose1#clear ip access-list counters SanJose1#show ip access-list 3-3 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. Standard IP access list 50 deny 192.168.60.0, wildcard bits 0.0.0.255 deny 192.168.70.0, wildcard bits 0.0.0.255 deny 192.168.80.64, wildcard bits 0.0.0.31 permit any Extended IP access list 100 deny tcp any 192.168.90.0 0.0.0.255 eq www deny tcp any 192.168.90.0 0.0.0.255 eq ftp deny tcp any 192.168.91.0 0.0.0.255 eq www deny tcp any 192.168.91.0 0.0.0.255 eq ftp deny icmp any host 192.168.60.1 permit ip any any Extended IP access list protect_acctg_servers deny tcp 192.168.60.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.70.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.80.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.90.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www deny tcp 192.168.91.0 0.0.0.255 192.168.10.0 0.0.0.7 eq www permit ip any any (5 matches) SanJose1# Step 3 The show ip arp command. Type the show ip arp command and look over the results. Notice that only the LAN interfaces and any hosts connected to them appear in the ARP table. You also get the MAC address, encapsulation type, and the local interface to which the address has been mapped. There is a show arp command that seems to yield the same result. SanJose1#show ip arp Protocol Address Age (min) Hardware Addr Type Interface Internet 192.168.1.10 1 00a0.cc23.fe40 ARPA Ethernet0 Internet 192.168.1.1 - 0010.7b3a.3f60 ARPA Ethernet0 Internet 192.168.4.1 - 0010.7b3a.3f60 ARPA Ethernet0 SanJose1# Type the show appletalk arp command and look over the results. You should only get a single entry unless you have attached some Mac hosts. SanJose1#show appletalk arp Address Age (min) Type Hardware Addr Encap Interface 57.76 - Hardware 0010.7b3a.3f60.0000 SNAP Ethernet0 SanJose1# An attempt to type the show ipx arp command will remind you that IPX does not use ARP. Step 4 The show ip route command. Type the show ip route command to display the IP route table. Because of a series of loopback addresses and a variety of protocols configured on both routers, you should see a pretty extensive display. Note that on SanJose1 there are some EX - EIGRP external and IA - OSPF inter area routes. 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 4-4 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set R 192.168.91.0/24 [120/1] via 192.168.0.2, 00:00:21, Serial0 R 192.168.90.0/24 [120/1] via 192.168.0.2, 00:00:21, Serial0 C 192.168.30.0/24 is directly connected, Loopback2 D EX 192.168.60.0/24 [170/2297856] via 192.168.0.2, 05:49:49, Serial0 C 192.168.10.0/24 is directly connected, Loopback0 C 192.168.40.0/24 is directly connected, Loopback3 192.168.95.0/32 is subnetted, 1 subnets O IA 192.168.95.1 [110/65] via 192.168.0.2, 05:49:49, Serial0 C 192.168.4.0/24 is directly connected, Ethernet0 D 192.168.80.0/24 [90/2297856] via 192.168.0.2, 05:49:49, Serial0 C 192.168.20.0/24 is directly connected, Loopback1 192.168.96.0/32 is subnetted, 1 subnets O IA 192.168.96.1 [110/65] via 192.168.0.2, 05:49:50, Serial0 C 192.168.0.0/24 is directly connected, Serial0 C 192.168.50.0/24 is directly connected, Loopback4 C 192.168.1.0/24 is directly connected, Ethernet0 R 192.168.2.0/24 [120/1] via 192.168.0.2, 00:00:24, Serial0 D EX 192.168.70.0/24 [170/2297856] via 192.168.0.2, 05:49:51, Serial0 R 192.168.3.0/24 [120/1] via 192.168.0.2, 00:00:24, Serial0 SanJose1# Type the show ip route summary command to see the routes summarized plus overhead and bytes used. Note that it also provides an additional summary of OSPF network information. SanJose1#show ip route summary IP routing table name is Default-IP-Routing-Table(0) Route Source Networks Subnets Overhead Memory (bytes) connected 8 0 416 1120 static 0 0 0 0 eigrp 90 3 0 156 420 ospf 100 0 2 104 280 Intra-area: 0 Inter-area: 2 External-1: 0 External-2: 0 rip 4 0 208 560 igrp 90 0 0 0 0 internal 2 2320 Total 17 2 884 4700 Type the show ip route ? command to see the parameter options available. Adding parameters like connected, static, or the routing protocols filters the output. SanJose1#show ip route ? bgp Border Gateway Protocol (BGP) connected Connected egp Exterior Gateway Protocol (EGP) eigrp Enhanced Interior Gateway Routing Protocol (EIGRP) igrp Interior Gateway Routing Protocol (IGRP) isis ISO IS-IS list IP Access list mobile Mobile routes odr On Demand stub Routes ospf Open Shortest Path First (OSPF) profile IP routing table profile rip Routing Information Protocol (RIP) static Static routes summary Summary of all routes supernets-only Show supernet entries only traffic-engineering Traffic engineered routes vrf Display routes from a VPN Routing/Forwarding instance | Output modifiers <cr> 5-5 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. Type the following commands: show ip route eigrp, show ip route ospf, and show ip route rip to see that you can be selective about what is displayed. SanJose1#show ip route eigrp D EX 192.168.60.0/24 [170/2297856] via 192.168.0.2, 05:55:25, Serial0 D 192.168.80.0/24 [90/2297856] via 192.168.0.2, 05:55:25, Serial0 D EX 192.168.70.0/24 [170/2297856] via 192.168.0.2, 05:55:25, Serial0 SanJose1# SanJose1#show ip route ospf 192.168.95.0/32 is subnetted, 1 subnets O IA 192.168.95.1 [110/65] via 192.168.0.2, 05:55:38, Serial0 192.168.96.0/32 is subnetted, 1 subnets O IA 192.168.96.1 [110/65] via 192.168.0.2, 05:55:38, Serial0 SanJose1# SanJose1#show ip route rip R 192.168.91.0/24 [120/1] via 192.168.0.2, 00:00:23, Serial0 R 192.168.90.0/24 [120/1] via 192.168.0.2, 00:00:23, Serial0 R 192.168.2.0/24 [120/1] via 192.168.0.2, 00:00:23, Serial0 R 192.168.3.0/24 [120/1] via 192.168.0.2, 00:00:23, Serial0 SanJose1# Type the show ip route address command for a host or network address on the other router to see the source and detail information about that route. SanJose1#show ip route 192.168.2.51 Routing entry for 192.168.2.0/24 Known via "rip", distance 120, metric 1 Redistributing via rip Last update from 192.168.0.2 on Serial0, 00:00:01 ago Routing Descriptor Blocks: * 192.168.0.2, from 192.168.0.2, 00:00:01 ago, via Serial0 Route metric is 1, traffic share count is 1 SanJose1# Step 5 The show ip interface command. Type the show ip interface command to display the IP interfaces. While the command displays all interfaces, let’s look at the LAN interface. Not only can we see the IP address, but we see that a second IP address has been assigned to the interface (192.168.4.1/24). We can see that there are both inbound and outbound access lists implemented – we would refer back to our show ip access-list to see what they do. Finally, the Multicast reserved group (224.0.0.9) tells us that this interface participates in RIP version 2 routing updates. SanJose1#show ip interface Ethernet0 is up, line protocol is up Internet address is 192.168.1.1/24 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1500 bytes Helper address is not set Directed broadcast forwarding is disabled Secondary address 192.168.4.1/24 Multicast reserved groups joined: 224.0.0.9 Outgoing access list is 50 Inbound access list is 100 Proxy ARP is enabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent 6-6 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. ICMP mask replies are never sent IP fast switching is enabled IP fast switching on the same interface is disabled IP Flow switching is disabled IP Feature Fast switching turbo vector IP multicast fast switching is enabled IP multicast distributed fast switching is disabled Router Discovery is disabled IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Probe proxy name replies are disabled Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabled SanJose1# Using the same skills, we can see that Loopback 2 is participating in OSPF while Loopback 3 is participating in EIGRP. SanJose2 should have a similar variety of routing protocols. Loopback2 is up, line protocol is up Internet address is 192.168.30.1/24 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1514 bytes Helper address is not set Directed broadcast forwarding is disabled Multicast reserved groups joined: 224.0.0.5 224.0.0.6 Loopback3 is up, line protocol is up Internet address is 192.168.40.1/24 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1514 bytes Helper address is not set Directed broadcast forwarding is disabled Multicast reserved groups joined: 224.0.0.10 Outgoing access list is not set Make sure that you know the difference between the show ip interface command and the show interface command. As you saw in the examples the show ip interface command displays the status of features and options on the interface. The show interface command includes the MAC address and a variety of performance counters that can be used to gauge the device’s usage. For example, the sample data below shows both the input and output statistics. It also shows that the queuing strategy is FIFO (first in / first out). SanJose1#show interface Ethernet0 is up, line protocol is up Hardware is Lance, address is 0010.7b3a.3f60 (bia 0010.7b3a.3f60) Internet address is 192.168.1.1/24 MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:12, output 00:00:04, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 413 packets input, 98679 bytes, 0 no buffer 7-7 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. Received 294 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 766 packets output, 73002 bytes, 0 underruns 0 output errors, 0 collisions, 4 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Step 6 The show ip protocols command. Type the show ip protocols command to display the supported protocols. While the command displays all protocols, let’s look at the OSPF. The command displays the process ID (100), the networks using OSPF and the Administrative Distance. SanJose1#show ip protocols Routing Protocol is "ospf 100" Sending updates every 0 seconds Invalid after 0 seconds, hold down 0, flushed after 0 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Redistributing: ospf 100 Routing for Networks: 192.168.0.0 192.168.10.0 192.168.20.0 192.168.30.0 Routing Information Sources: Gateway Distance Last Update 192.168.96.1 110 06:20:51 Distance: (default is 110) The IGRP output displays the AS number (90), the network using IGRP, that it is redistributing EIGRP, the various timers and the Administrative Distance. The IGRP metric weights show that the metric has not been modified. Routing Protocol is "igrp 90" Sending updates every 90 seconds, next due in 28 seconds Invalid after 270 seconds, hold down 280, flushed after 630 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Default networks flagged in outgoing updates Default networks accepted from incoming updates IGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 IGRP maximum hopcount 100 IGRP maximum metric variance 1 Redistributing: igrp 90, eigrp 90 Routing for Networks: 192.168.50.0 Routing Information Sources: Gateway Distance Last Update Distance: (default is 100) The EIGRP output displays the AS number (90), the networks using EIGRP, that it is redistributing IGRP, that automatic address summarization is on, the various timers and both Administrative Distance. The IGRP metric weights show that the metric has not been modified. Routing Protocol is "eigrp 90" Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Default networks flagged in outgoing updates Default networks accepted from incoming updates 8-8 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Redistributing: igrp 90, eigrp 90 Automatic network summarization is in effect Automatic address summarization: 192.168.0.0/24 for Ethernet0, Loopback0, Loopback1 Loopback2, Loopback3, Loopback4 192.168.40.0/24 for Ethernet0, Loopback0, Loopback1 Loopback2, Loopback4, Serial0 Routing for Networks: 192.168.0.0 192.168.40.0 Routing Information Sources: Gateway Distance Last Update 192.168.0.2 90 06:20:55 Distance: internal 90 external 170 The RIP output displays the networks using RIP, that version 2 is being used, the various timers and the Administrative Distance. The IGRP metric weights show that the metric has not been modified. Routing Protocol is "rip" Sending updates every 30 seconds, next due in 24 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: rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain Ethernet0 2 2 Serial0 2 2 Routing for Networks: 192.168.0.0 192.168.1.0 Interface Send Recv Triggered RIP Key-chain 192.168.4.0 Routing Information Sources: Gateway Distance Last Update 192.168.0.2 120 00:00:25 Distance: (default is 120) Note there is no similar command for either AppleTalk or IPX. Step 7 The show protocols command. Type the show protocols command to summarize each interface and the network protocols associated with them. There is a Global values: summary of all network protocols enabled on the router. SanJose1#show protocols Global values: Internet Protocol routing is enabled Appletalk routing is enabled IPX routing is enabled Ethernet0 is up, line protocol is up Internet address is 192.168.1.1/24 AppleTalk address is 57.76, zone A IPX address is 30.0010.7b3a.3f60 Loopback0 is up, line protocol is up Internet address is 192.168.10.1/24 IPX address is 31.0000.1111.1111 Loopback1 is up, line protocol is up Internet address is 192.168.20.1/24 IPX address is 32.0000.1111.1111 9-9 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. Loopback2 is up, line protocol is up Internet address is 192.168.30.1/24 IPX address is 33.0000.1111.1111 Loopback3 is up, line protocol is up Internet address is 192.168.40.1/24 Loopback4 is up, line protocol is up Internet address is 192.168.50.1/24 Serial0 is up, line protocol is up Internet address is 192.168.0.1/24 AppleTalk address is 18.153, zone A IPX address is 20.0000.1111.1111 Serial1 is administratively down, line protocol is down SanJose1# Step 8 The show ip traffic command. Type the show ip traffic command to summarize IP protocol activity since the last clear command or the router rebooted. The IP statistics summarizes the broadcast and multicast activity as well as revealing that there were encapsulation failures. SanJose1#show ip traffic IP statistics: Rcvd: 50588 total, 20545 local destination 0 format errors, 0 checksum errors, 1 bad hop count 0 unknown protocol, 0 not a gateway 0 security failures, 0 bad options, 0 with options Opts: 0 end, 0 nop, 0 basic security, 0 loose source route 0 timestamp, 0 extended security, 0 record route 0 stream ID, 0 strict source route, 0 alert, 0 cipso 0 other Frags: 0 reassembled, 0 timeouts, 0 couldn't reassemble 0 fragmented, 0 couldn't fragment Bcast: 2403 received, 378 sent Mcast: 13923 received, 15700 sent Sent: 21297 generated, 26539 forwarded Drop: 10 encapsulation failed, 0 unresolved, 0 no adjacency 555 no route, 0 unicast RPF, 0 forced drop Type the ICMP statistics will vary depending on whether you did the ping and trace exercises during this session ICMP statistics: Rcvd: 0 format errors, 0 checksum errors, 0 redirects, 4 unreachable 2891 echo, 15 echo reply, 16 mask requests, 0 mask replies, 0 quench 0 parameter, 0 timestamp, 0 info request, 0 other 8 irdp solicitations, 0 irdp advertisements Sent: 0 redirects, 262 unreachable, 22 echo, 2831 echo reply 0 mask requests, 0 mask replies, 0 quench, 0 timestamp 0 info reply, 0 time exceeded, 0 parameter problem 0 irdp solicitations, 0 irdp advertisements UDP statistics: Rcvd: 3051 total, 1263 checksum errors, 1787 no port Sent: 2723 total, 0 forwarded broadcasts TCP statistics: Rcvd: 1343 total, 0 checksum errors, 0 no port Sent: 2104 total Probe statistics: Rcvd: 0 address requests, 0 address replies 0 proxy name requests, 0 where-is requests, 0 other Sent: 0 address requests, 0 address replies (0 proxy) 0 proxy name replies, 0 where-is replies 10-10 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc. EGP statistics: Rcvd: 0 total, 0 format errors, 0 checksum errors, 0 no listener Sent: 0 total IGRP statistics: Rcvd: 0 total, 0 checksum errors Sent: 303 total OSPF statistics: Rcvd: 2508 total, 0 checksum errors 2446 hello, 3 database desc, 0 link state req 14 link state updates, 14 link state acks Sent: 2477 total IP-IGRP2 statistics: Rcvd: 10577 total Sent: 10580 total PIMv2 statistics: Sent/Received Total: 0/0, 0 checksum errors, 0 format errors Registers: 0/0, Register Stops: 0/0, Hellos: 0/0 Join/Prunes: 0/0, Asserts: 0/0, grafts: 0/0 Bootstraps: 0/0, Candidate_RP_Advertisements: 0/0 IGMP statistics: Sent/Received Total: 0/0, Format errors: 0/0, Checksum errors: 0/0 Host Queries: 0/0, Host Reports: 0/0, Host Leaves: 00 DVMRP: 0/0, PIM: 0/0 ARP statistics: Rcvd: 351 requests, 0 replies, 0 reverse, 0 other Sent: 0 requests, 10 replies (0 proxy), 29 reverse SanJose1# Step 9 The show cdp neighbor [detail] command. Type the show cdp neighbor command to use the Cisco Discovery Protocol to gather information on adjacent devices. The lab output should show a router on one side and a switch on the other. Keep in mind that only Cisco devices will be detected. SanJose1# show cdp neighbors Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater Device ID Local Intrfce Holdtme Capability Platform Port ID Switch Eth 0 143 T S WS-C2924M-Fas 0/22 SanJose2 Ser 0 164 R 2524 Ser 0 SanJose1# Type the show cdp neighbor detail command to get a more in depth view of the neighbor devices. In the following output we see that the unnamed switch is a model 2924M-XL running version 12.0(5) of the IOS. The router SanJose2 is a 2524 running version 12.0(5)T of the IOS and is configured to support IP, Novell, and Appletalk. We also have one interface address for each protocol. SanJose1# show cdp neighbors detail Device ID: Switch Entry address(es): Platform: cisco WS-C2924M-XL, Capabilities: Trans-Bridge Switch Interface: Ethernet0, Port ID (outgoing port): FastEthernet0/22 Holdtime : 136 sec [...]... other EIGRP options Step 14 The debug ip igrp ? command Type the debug ip igrp ? command to see the options for debugging IGRP routing activity As a distance vector protocol the updates are regular, but at a 90-second interval, so be patient The debug ip igrp events command shows a summary of activity while the debug ip igrp transactions command shows the details SanJose1 #debug ip igrp ? events IGRP protocol... RIP-TIMER: periodic timer expired SanJose1#un all All possible debugging has been turned off SanJose1# Step 12 The debug ip ospf command Type the debug ip ospf ? command to see the options for debugging OSPF routing activity The debug ip ospf events command logs each OSPF activity with route, area, source interface, and source address information SanJose1 #debug ip ospf ? adj OSPF adjacency events database-timer... (192.168.50.1) and 0 exterior routes Loopback4 (192.168.50.1) Loopback4 (192.168.50.1) There probably shouldn’t be any incoming updates on either router because EIGRP is used on the serial link Step 15 The debug ip icmp command Type the debug ip icmp command to see the results of ping and trace activity The Cisco trace and TCP/IP tracert commands both use the TTL feature in a 15-15 Semester 8 Internetwork Troubleshooting. .. Step 10 The show tcp commands Type the show tcp ? command to see TCP activity Particularly the show tcp statistics command gives a good summary of TCP traffic sent and received SanJose1 #show aux brief console statistics tcb vty | tcp ? Line number Auxiliary line Brief display Primary terminal line TCP protocol statistics TCB address Virtual terminal Output modifiers SanJose1 #show tcp statistics... and an ICMP message sent This continues until there is a trail to the destination device The final router returns an ICMP destination unreachable reply The following is an example After running the debug ip icmp command, ping the host on the other router to confirm its existence and connectivity Then run a trace command to the same host and look over the results SanJose1 #debug ip icmp ICMP packet debugging... via 0.0.0.0 in 1 hops Try the debug ip rip ? command to see the optional parameters There are three options Try the debug ip rip database command to see the actual entries as they are added to the RIP database SanJose1 #debug ip rip ? database RIP database events events RIP protocol events trigger RIP trigger extension SanJose1 #debug ip rip database RIP database events debugging is on SanJose1# 11:30:05:... 13 The debug ip eigrp ? command Type the debug ip eigrp ? command to see the options for debugging EIGRP routing activity As with OSPF, EIGRP routing updates are triggered events, so you may need to trigger a link or database change to see anything happen In the following example, after waiting several minutes during which time nothing happened, I cleared the Neighbor database Try the steps shown below... Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc 1 Connections closed (including 0 dropped, 0 embryonic dropped) 0 Total rxmt timeout, 0 connections dropped in rxmt timeout 0 Keepalive timeout, 0 keepalive probe, 0 Connections dropped in keepalive SanJose1 #show tcp brief Step 11 The debug ip rip command Type the debug ip rip command to see the result of... rcv from 192.168.0.2 SanJose1# 12:36:40: ICMP: dst (192.168.0.1) port unreachable rcv from 192.168.0.2 SanJose1# Note Other debug and show commands will be covered in detail in later chapters where their usage can be tied to a troubleshooting activity 16-16 Semester 8 Internetwork Troubleshooting v1.0 - Lab 4.6.3 Copyright  2001, Cisco Systems, Inc ... cleared the Neighbor database Try the steps shown below You should see both sent and received updates SanJose1 #debug ip eigrp ? AS number neighbor IP-EIGRP neighbor debugging notifications IP-EIGRP event notifications summary IP-EIGRP summary route processing SanJose1 #debug ip eigrp IP-EIGRP Route Events debugging is on SanJose1#clear ip eigrp neighbor SanJose1# 12:06:39: IP-EIGRP: 192.168.0.0/24 . the show ip interface command and the show interface command. As you saw in the examples the show ip interface command displays the status of features and. The debug ip icmp command. Type the debug ip icmp command to see the results of ping and trace activity. The Cisco trace and TCP/IP tracert commands