Tài liệu Catalyst 3900 Troubleshooting ppt

Catalyst 3900 Troubleshooting Catalyst 3900 Troubleshooting Contents ● Introduction ● Using the Statistics Menu ● Using the Display Summary Screen ● Using the Message Log Information Screen ● Using the Switch Statistics Screen to Check the Total Throughput ● Troubleshooting Port Connectivity and Throughput problems ● Using the Port Status Screen to Check the Configuration ● Troubleshooting Address Table Problems ● Troubleshooting Spanning Tree Problems ● Checking the VLAN Statistics ● Checking the VTP Statistics ● Related Information Introduction This document describes how to use the Cisco Catalyst 3900 Statistics screens to help troubleshoot various switching scenarios. It presents some of the most common problems faced with the 3900 switch and how the Statistics screens can be used to identify them.You can use the Token Ring acronyms document to explain some of the acronyms used. The document concentrates on the following areas: ● Display Summary - The most important configuration and operational settings on the 3900 switch ● Message Log - Important event and error messages the 39000 switch has logged ● Switch Statistics - The behavior of the 3900 switch as a whole ● Port Status and Statistics - Looking at the type of traffic on individual ports ● Address Tables - Looking at the internal switching tables to see from which port an address has been learned ● Spannning Tree Information - Looking at the various spanning tree modes running at the TrBRF and TrCFRF level These areas are explained in more detail below. Using the Statistics Menu http://www.cisco.com/warp/public/482/cat3900_ts.html (1 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting This is the main Statistics menu for the Catalyst 3900. The screens described below are all accessible from here. The information on all of the statistics menu screens is refreshed approximately every five seconds. Using the Display Summary Screen http://www.cisco.com/warp/public/482/cat3900_ts.html (2 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The display summary will probably be the first menu you will go to when troubleshooting the Catalyst 3900 switch. It will provide you with a detailed summary of the most important configuration and operational parameters. In most situations this will be the most powerful tool for you to use to troubleshoot the 3900 switch. The information it will give you will include: ● Switch/Stack information ● VLAN configuration ● IP configuration ● SNMP configuration ● CDP configuration ● Module configuration ● Spanning Tree information ● Port Status information ● Message log ● Hardware diagnostics Many of the problems on the Catalyst 3900 switch are caused by running a back level release of software. One of the first uses of the display summary should be to check the software level which can be found under the Switch/stack information section. Make sure that you are running the latest software release available. A very common cause of problems on the 3900 switch is a software misconfiguration. Check the software configuration which can be found under the VLAN configuration section carefully for any errors. Check especially that ring numbers configured between a 3900 switch and a router match (ring numbers are defined in decimal on a router and in hex on the 3900 switch). Another very common cause of problems on the 3900 switch is an error in the Spanning Tree modes selected at the BRF and CRF levels. Use the Spanning Tree information section to carefully check that you have the correct Spanning Trees running. Refer to Catalyst 3900 Spanning Tree Modes. for assistance. Much of the information in the summary display can be viewed individually by using the menus explained in the following sections of this guide. Using the Message Log Information Screen http://www.cisco.com/warp/public/482/cat3900_ts.html (3 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting After the Display Summary, the Message Log Information screen will probably be the second menu that you will most commonly go to when troubleshooting the Catalyst 3900 switch. It will provide you with detailed information about events that have happened on the Catalyst 3900. Use this log history information to gain an understanding of events that have been logged on the Catalyst 3900. Using the Switch Statistics Screen to Check the Total Throughput http://www.cisco.com/warp/public/482/cat3900_ts.html (4 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The Switch Statistics Menu gives us the following information about the Catalyst 3900 switch as a whole: system up time, environmental statistics, stations in use, traffic and error counters. Use this screen to get an idea of the quantity of traffic the 3900 switch is passing (Frames Transmitted/Received and Currently active Stations/Largest Number of Stations counters). Check the Error Frames Received/Frames Lost counters to identify whether the 3900 switch is losing frames or receiving corrupted or non switchable frames from one or more of its ports. Notice there is the equivalent of a clear counters at the bottom of the screen. Use the Reset option to set a fresh timemark by which to collect statistics. Troubleshooting Port Connectivity and Throughput Problems http://www.cisco.com/warp/public/482/cat3900_ts.html (5 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The following options are displayed from this menu: ● General Statistics - Select this option to view general port statistics. ● 802.5 Statistics - Select this option to view 802.5 port statistics. ● 802.5 State Information - Select this option to view 802.5 state information for each port. ● 802.5 DTR MAC Information - Select this option to view dedicated Token Ring information for each port. Selecting the General Statistics option will display the menu below: http://www.cisco.com/warp/public/482/cat3900_ts.html (6 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The General Statistics screen for an individual port is the closest to a Token Ring sniffer that the Catalyst 3900 switch can become. It gives you detailed information on the amount and type of packets that are being received and transmitted on this port. By monitoring this screen (refreshed every five seconds) you will be able to build an idea of the type and amount of traffic passing through the selected port. The most common problems you will use this screen to troubleshoot for are packets that are not being forwarded or that are being dropped. Check carefully the NSR, SRF, STE and ARE counters and compare the packet types they represent to the rules of the Catalyst 3900 Spanning Tree Modes. A common problem is an incorrectly configured Spanning Tree mode which prevents some of these packet types from being forwarded. Check the total amount of frames being received and transmitted to see how busy this port is. Check the counters on the right hand side to see if there is congestion or a problem on the physical Token Ring connecting to this port. Another problem you might see from the STE annd ARE counters on this screen is an explorer storm. If you think that you have a problem with an explorer storm then the following two options are available on the Catalyst 3900 switch: ● Reduce the hop count limit for ARE and STE explorers to the lowest value needed within your network. Change the ARE and SRE values from the VLAN Parameter Configuration for TrCRF menu below: http://www.cisco.com/warp/public/482/cat3900_ts.html (7 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting ● Reduce the maximum explorer rate permitted on an individual port to the lowest value needed within your network. Change the maximum explorer rate value from the Token Ring Port Configuration menu below: http://www.cisco.com/warp/public/482/cat3900_ts.html (8 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting From the 802.5 DTR MAC Information menu option the following menu is presented: The following options are displayed on this menu: ● TXI Information - Select this option to view dedicated Token Ring TXI information. http://www.cisco.com/warp/public/482/cat3900_ts.html (9 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting ● Station-CPort Information - Select this option to view dedicated Token Ring station-Cport information. Selecting the TXI Information option will display the menu below: Use this screen to gain information about the physical functioning of the Tokenring. You would typically use this screen if you suspected a problem with the Tokenring itself, such as beaconing. Selecting the 802.5 Statistics and State Information options will display the menus below: http://www.cisco.com/warp/public/482/cat3900_ts.html (10 of 23) [5/5/2001 10:41:48 PM] [...]... from the Catalyst 3900 main menu You will then be taken to the menu below which gives an option to reset the Port Address Table: http://www.cisco.com/warp/public/482/cat3900_ts.html (14 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting Another problem that can be found on the Catalyst 3900 switch is that of not being able to pass traffic between different ports The twenty ports in a 3900 switch... From the Catalyst 3900 main menu enter CNTL-T 2 Enter the password for the 3900 switch 3 From the vin> command line prompt enter the 'qtprst R' command as in the screenshot below: http://www.cisco.com/warp/public/482/cat3900_ts.html (15 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting 4 Finally from the vin> command line prompt enter the conset command to return to the Catalyst 3900 main... Configuration menu below: http://www.cisco.com/warp/public/482/cat3900_ts.html (11 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting Choose the Soft Error Monitoring option to set the desired threshold and interval for the port: http://www.cisco.com/warp/public/482/cat3900_ts.html (12 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting Using the Port Status Screen to Check the Configuration... address table Troubleshooting Spanning Tree Problems http://www.cisco.com/warp/public/482/cat3900_ts.html (19 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The above screen will provide you with the current Spanning Tree Information that you have configured on the BRF Use this screen to troubleshoot a problem with spanning tree at the BRF level Use the rules within Catalyst 3900 Spanning.. .Catalyst 3900 Troubleshooting The information on the above two screens is the Catalyst 3900 switches equivalent of the show controllers tokenring xx command on a router You should use it in a similar context Troubleshooting for physical problems with the Tokenring segment the port is connected to Remember... Forwarding modes configured Notice the values here are the same values that you would have configured in the port configuration screen Troubleshooting Address Table Problems http://www.cisco.com/warp/public/482/cat3900_ts.html (13 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The following options are displayed on the above panel: q q q q Master Address Table - View all of the destination... http://www.cisco.com/warp/public/482/cat3900_ts.html (20 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The above screen will provide you with the Current Spanning Tree Information that you have configured on the CRF Use this screen to troubleshoot a problem with spanning tree at the CRF level Check the Spanning Tree mode you are using in the Protocol field above and make sure that it is correct, using the rules within the Catalyst. .. above and make sure that it is correct, using the rules within the Catalyst 3900 Spanning Tree Modes to assist you Note: Remember that there is a different instance of spanning tree running in every VLAN Checking the VLAN Statistics http://www.cisco.com/warp/public/482/cat3900_ts.html (21 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The above screen will provide you with the VLAN Statistics... VTP Statistics The above screen will provide you with the VTP Statistics for the switch Refer to the VTP section of the Managing the 3900 Configuration Guide for more information on how to use this screen Related Information q q q q Managing Your Catalyst 3900 Catalyst 3900 Token Ring Inter-Switch Link Module Configuration Note The Multiple Trap Recipients section of System Level Configuration Configuring... this would probably require a reset of the port address table Selecting the VLAN Address Table option will display the menu below: http://www.cisco.com/warp/public/482/cat3900_ts.html (17 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting The above screen will provide you with the same information as the master address table, but on a per VLAN basis Use the above screen to gain information . Catalyst 3900 Troubleshooting Catalyst 3900 Troubleshooting Contents ● Introduction ● Using the Statistics. http://www.cisco.com/warp/public/482/cat3900_ts.html (1 of 23) [5/5/2001 10:41:48 PM] Catalyst 3900 Troubleshooting This is the main Statistics menu for the Catalyst 3900. The screens