By default, the eG agent automatically discovers the interface that is to be used for packet capture. This is why, the ADAPTER DEVICE SELECTION flag is set to Automatic by default. However, if you want to manually override this discovery process, then, you can do either of the following:
- Set the ADAPTER DEVICE SELECTION flag to Manual, (OR)
- Edit the eg_desktop.ini file (in the <eg_agent_install_dir>\agent\config directory) to manually configure the adapter you want the test to use.
Both these options have been discussed below:
Seting the ADAPTER DEVICE SELECTION flag to Manual
If this is done, then two new parameters, namely - DEVICE NAME and DEVICE ID - will automatically appear in the test configuration page. Click on the Discover button next to the DEVICE NAME parameter to trigger the discovery of the adapters supported by the monitored host. Once discovery is complete, all discovered adapters will populate the DEVICE NAME drop-down. From this drop-down, select the adapter that you want test to use. As soon as the DEVICE NAME is selected, the ID of the chosen adapter will automatically appear against the DEVICE ID box. Then, click on the Update button to register the changes.
Editing the eg_desktop.ini file to manually specify the adapter name
The eg_desktop.ini file on the agent side drives how the eG agent monitors packets transmissions to and from the client desktop. The example below shows a sample eg_desktop.ini file that can be found in the <EG_INSTALL_DIR>\agent\config directory.
[EG_CONFIG]
Interface=
Ports=80,1494,7077,53,3389,2598
CacheTime=1
RemoteServers=Web:*:80:C,Dns:*:53:C,Citrix1494:*:1494:C,Citrix2598:*:2598:C,TerminalService:*:3389:C
;DynamicServers=80:C,1494:C,2598:C
By default, the eG agent automatically discovers the interface that is to be used for packet capture. By setting the Interface value in this file, it is possible to manually override the discovery process. To know what interfaces are available on the system, check the agent log file (<EG_INSTALL_DIR>\agent\logs\error_log). For instance, say that the error_log of the agent monitoring the client desktop contains the following entries:
04/06/2012 06:57:32 INFO Agent: Available packet capture devices are: \Device\NPF_{3B44EC4D-45DB-4276-AC45-00C53206305E}
NOC Extranet Access Adapter (Microsoft's Packet Scheduler) ,\Device\NPF_{F6625292-945E-420B-B207-F4E485BE3625}
DW1530 Wireless-N WLAN Half-Mini Card (Microsoft's Packet Scheduler) ,\Device\NPF_{DF81BA02-9585-4691-83A5-0420969E0DD9}
Intel(R) 82579LM Gigabit Network Connection (Microsoft's Packet Scheduler)
04/06/2012 06:57:32 INFO Agent: Enabling packet capture enabled using device \Device\NPF_{3B44EC4D-45DB-4276-AC45-00C53206305E}
Intel(R) 82579LM Gigabit Network Connection (Microsoft's Packet Scheduler)
From these entries, it is evident that the desktop being monitored supports the following adapters:
- \Device\NPF_{3B44EC4D-45DB-4276-AC45-00C53206305E} NOC Extranet Access Adapter (Microsoft's Packet Scheduler)
- \Device\NPF_{F6625292-945E-420B-B207-F4E485BE3625} DW1530 Wireless-N WLAN Half-Mini Card (Microsoft's Packet Scheduler)
- \Device\NPF_{DF81BA02-9585-4691-83A5-0420969E0DD9} Intel(R)
Also, the entry 04/06/2012 06:57:32 INFO Agent: Enabling packet capture enabled using device \Device\NPF_{3B44EC4D-45DB-4276-AC45-00C53206305E}, clearly indicates that the eG agent is currently using the adapter, \Device\NPF_{3B44EC4D-45DB-4276-AC45-00C53206305E}, for packet capture. If you prefer to use one of the other two adapters - say, \Device\NPF_{F6625292-945E-420B-B207-F4E485BE3625} - for packet capture, change your Interface setting as described below:
Interface=\Device\NPF_{F6625292-945E-420B-B207-F4E485BE3625}
Then, save the file and restart the eG agent.
Note:
If you have picked a DEVICE NAME from the admin interface and also manually specified a different device name against the Interface parameter in the eg_desktop.ini file, the DEVICE NAME specification will override the Interface specification.
In addition to specifying the Interface to use, you can also specify the Ports, Cache time, RemoteServers, and DynamicServers for the test using the eg_desktop.ini file. The Ports specification specifies the ports that the packet capture is set to process. Packets transmitted to other ports are not considered in the traffic analysis done by the eG agent. Note also that the eG agent currently only monitors TCP protocol traffic (i.e., UDP traffic is not analyzed).
The eG agent can be configured to monitor all traffic on a specific port, or just traffic to specific servers. This configuration is provided in the RemoteServers specification. The right hand side setting for this configuration is a comma-separated list. Entries in the list are in the format name:ip address patterns:portNumber:C, where the name is the display name indicated in the eG monitor interface, and the ip address pattern is a pattern specifying the IP addresses for which traffic is to be monitored (e.g., 192.168.10.7 specifies a specific server to monitor, while 192.168.10.* represents all servers whose IP addresses match the specified pattern). The port number is the specific port number to be monitored. Multiple entries corresponding to the same name are allowed and for such entries, performance statistics are aggregated while reporting (i.e., Web:192.168.10.7:80:C,web:203.197.*:80:C is allowed and traffic to all servers matching the IP address pattern will be reported as traffic for the Web descriptor).
If you are not aware of the exact IP addresses or IP address patterns of the servers with which the client desktop communicates, then, you can configure the eG agent to monitor all traffic from the client desktop to a specific set of server ports. To achieve this, simply uncomment the DynamicServers specification by removing the ‘;’ that precedes this specification. The server ports that the eG agent will be monitoring are specified on the right hand side of this entry in the format, portnumber:C. To enable the eG agent to monitor more number of ports, you can append to the comma-separated list of ports available on the right hand side of the DynamicServers specification. Then, save the file and restart the eG agent.