School of Information Technology and Engineering (SITE) CEG 4395: Computer Network Management. Lab 4: Remote Monitoring (RMON) Operations

Transcription

1 School of Information Technology and Engineering (SITE) CEG 4395: Computer Network Management Lab 4: Remote Monitoring (RMON) Operations Objective To become familiar with basic RMON operations, alarms, and events. Background Study lecture 15, as well as chapter 8 in the book for a review of ROMN. Setup Each lab group should be stationed at a workstation that consists of a PC and a CISCO 2600 router. For this particular lab, you will not use the router. Instead, you will share, with the lab group opposite yours, a CISCO Catalyst 2940 switch. For example, in the figure below, the group at Wks1 shares Switch 1 with the group at Wks2. Wks1 and Wks2 therefore form a supergroup. The lab is configured so that each workbench supports 6 workstations. There are 3 of these workbench arrangements in the CBY B402 Networking Lab. Wks1 Wks3 Wks5 Switch 1 Routers A Routers B Switch 2 Switch 3 Wks2 Wks4 Wks6 Router (R) Workstation (Wks) Switch (Sw) Figure 1. Workbench arrangements. You can choose any IP addresses that you want for the workstations, but the following addresses will be assumed for the lab.

2 Workstation IP Address IP Mask IP Gateway Wks Wks Software modules You will utilize 3 applications for this lab each one configured on the following workstations. Application NMS (HiFn Meterware) FTP Server (WAR FTP) FTP client (WS FTP) Location All workstations All workstations All workstations Connecting the Network Note that in order to make certain that the workstations are talking to each other it is not necessary to configure the switch at all. Just simply connect your workstation s Ethernet cable into the appropriate switch s port and after setting up the static IP addresses of the workstations you should be able to ping any of the workstations connected to the switch. Configuring the switch One person in each super-group should be the designated admin to configure the switch. You will need to choose that person and connect his/her workstation directly to the switch using the PC s serial connection. The switch supports the CISCO IOS that is similar to that used to configure the router therefore the commands used are the same as those used for the router except in configurations particular to the switch. Configuring the switch s IP address 1. Type enable to enter Privileged Mode. 2. Type the password Lab if prompted for a password. The prompt should now end with #. If there are difficulties with this password the TA will have to perform a clean boot. 3. Type conf t to enter into terminal configuration mode. 4. Type int vlan1 to configure interface vlan1 (the switch considers VLANs as interfaces. VLAN1 is the default VLAN for the switch). 5. Type ip address to set the switch s IP address and mask. 6. Exit the configuration levels by typing exit a couple of times to get to the EXEC level. 7. Confirm your configuration by typing show int vlan1 Configuring the switch for SNMP Management through an NMS Similar to the previous lab the switch needs to be configured to allow the NMS to manage it. The following sequence of commands is used to set up the SNMP community name and allow any NMS in the subnet to manage it. 1. Switch(config)# access-list 1 permit (note that the filter mask denotes that any terminal with the IP addresses from have permit permission. 2. Switch(config)# snmp-server community tei_admin RW 1 (configures the SNMP community name tei_admin for READ WRITE privileges for SNMP clients defined by access list 1.

3 3. Exit the configuration levels by typing exit a couple of times to get to the EXEC level. 4. Confirm your configuration by typing show running-conf and view the switch s SNMP information. You should now be finished configuring the switch and the RMON objects should be available to be configured and viewed by the NMS. Configuring the switch so that it can be managed via Telnet For this lab one of the groups will be directly connected to the switch while the other can query the switch via a telnet session. This set up can only be done by the designated admin. Once the configuration is done the other group can confirm that they can connect to the switch by running the telnet application on their PC and verifying that they can communicate to the CISCO IOS over the telnet session. Switch(config)# line vty 0 15 (Configures the number of Telnet sessions, all 16 in this case) password cbyb402 (enter the password as cbyb402 for telnet access). Note: For the reaming procedure, both groups can perform the exercises since the switch will accept multiple NMS connections. Procedure 1. RMON Basic Operations RMON Statistics and History Start up the HiFn NMS on the workstation The NMS should automatically discover the switch by entering its IP address as the seed value for the RMON search. If you do not enter a seed IP address when you launch the NMS, you can do an RMON Discovery from the Configuration Menu item of the HiFn NMS. (Note: Make certain the community name is tei_admin and choose to discover it once only). Once the switch is available in the summary view of HiFn it is possible to investigate the RMON Statistics group. 1. What type of SNMP level was discovered for the switch and what does it signify? Hint: You can search the HiFn online manual for the type of SNMP level. You can view any statistics on a port by right clicking on the switch icon in the HiFn summary view and choosing RMON -> statistics. You might get a window that prompts you for the interface to monitor but only if the switch is a Catalyst 2900 series switch (We have a couple of these in the lab but you should not be using one). Choose the port that the other workstation is connected to. You should get a window that is similar to that shown in figure 2. For the Catalyst 2940 switch it will default to the ifindex.1 interface and you will have to configure the Control table to change this to the interface port that corresponds to the FTP server. You do this by choosing the Table -> Control Tables from the Statistics RMON window. If you do this you will see a table similar to that shown in figure 3. If you add a new control table entry, such as interface 2, you will see a window like figure 4.

4 Figure 2. HiFn RMON display. Figure 3. The control table. Figure 4. New control table added. 2. How would you determine which interface index belongs to what particular port on the

5 switch? 3. Send out a broadcast ping to the subnet from the FTP server workstation. What packet rate and utilization do you see? To get a better sense of the statistic capture of RMON you need to configure the FTP server and perform some large file downloads. Configuring the FTP Server Each group in a super-group needs to run its FTP server so that opposite group can run its FTP client. Coordinate with the other group to do so. You will be using the WAR FTP server, which is configured as follows: Copy the file C:\Program Files\OPENXTRA\Ethereal\ethereal.exe to C:\Program Files\War-ftpd\FTPRoot\pub\ethereal.exe This will give the FTP client a relatively large file to download. Start the WARSVR by going to the Windows Service Manager Start->Control Panel Administrative Tools->Services. Start the War FTP Server manager by clicking on the icon in the lower right hand corner and when prompted for a password use cbyb From your workstation, connect to the FTP server of the opposite group and retrieve the file ethereal.exe. What is the packet rate that you see in the statistics window? Close this window. Take a look at the Flow index of this interface. You open this window by pressing on the tab icon on the HiFn summary window. Again you might be asked for the particular switch interface to monitor. 5. What do you notice about the results available from this RMON flow index? What type of traffic takes up the majority of the load? Why do you think that the network is showing such poor performance? Hint try the help menu (? icon). 6. What is the default performance rating scale for Good values for this graph? Hint: take a look at the Option -> Parameters menu option. 7. Transfer the file again using FTP. This time take a look again at the Traffic flow and see how it changes. What does the performance of the network look like? 8. In order to estimate a reasonable ratio of overhead to total traffic, open the Utilization window from the Monitor menu options. What is the percentage of overhead to total traffic? What is the ratio of access faults to the total traffic? What do the access faults represent? 9. One can also get RMON values by using the MIB browser. Show the value for the number of packets due to the traffic flow by viewing the following object in the RMON MIB: history.etherhistorytable.etherhistoryentry.etherhistorypkts When you do this you will probably also see the rows in the table that have been created by the other group s NMS. How do you determine which value of the many that exist in the etherhistorypkts table belongs to your NMS and was used for the Network Flow analysis graphs that you have been viewing? 2. RMON Alarms

6 Setting up an RMON alarm An RMON alarm can be configured using the NMS by right clicking on the device in the NMS summary window and choosing the RMON -> Alarms menu choice. If you do this you will get a window that looks similar to that shown in figure 5. Figure 5. Setting an RMON Alarm. 10. Using figure 5 and your lecture notes, give a short explanation as to how the RMON alarms are related to the RMON events. You have now achieved setting the alarm. Go ahead now and verify that you have accomplished this by transferring the large exe file from the FTP server and monitoring the NMS to see if the alarm is triggered. You can also monitor the logs by choosing to view the logs form the device menu. Questions 1. In this lab you simply considered triggering alerts based on capacity limits. Describe two other Alerts that could be defined using the RMON groups and describe under what circumstances you might use these Alerts.