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Path measurement: Difference between revisions
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* Enable analysis: This will disable or enable the path measurement feature. When disabled, no additional memory is used. When enabled, memory for the packet buffer is used which cannot be used for other analyzing modules thus reducing the maximum time the device can go back in time. | * Enable analysis: This will disable or enable the path measurement feature. When disabled, no additional memory is used. When enabled, memory for the packet buffer is used which cannot be used for other analyzing modules thus reducing the maximum time the device can go back in time. | ||
* Description of this master device: This field is only used for informational purposes to identify the master device. It can be freely chosen, for example to the location the device is installed. This field can also be left empty to use the default name | * Description of this master device: This field is only used for informational purposes to identify the master device. It can be freely chosen, for example to the location the device is installed. This field can also be left empty to use the default name '''master'''. | ||
The following | The following '''Remote device''' configuration section configures the access to the remote device: | ||
* Device IP or name: This is the IP address or host name of the remote device under which the master device can contact the remote device. The remote device must be accessible at the location of the master device. | * Device IP or name: This is the IP address or host name of the remote device under which the master device can contact the remote device. The remote device must be accessible at the location of the master device. | ||
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* Maximum packet delay: This field describes the maximum amount of seconds to wait for packet information from the remote device. | * Maximum packet delay: This field describes the maximum amount of seconds to wait for packet information from the remote device. | ||
:The settings must be saved but to actually take effect, a restart of the packet processing is necessary. If this step is required will tell so at the bottom of the page under | :The settings must be saved but to actually take effect, a restart of the packet processing is necessary. If this step is required will tell so at the bottom of the page under '''Required actions'''. | ||
Parameters currently in use: | Parameters currently in use: This section shows the current state of the measurement engine. The engine might be inactive even if the feature is enabled. Usually a restart is required to actually make it active. If active, the current packet delay is shown. It might be different from the selected value in the configuration above, but if so a note appears that a restart is required. | ||
This section shows the current state of the measurement engine. | |||
The engine might be inactive even if the feature is enabled. | |||
Usually a restart is required to actually make it active. | |||
If active, the current packet delay is shown. | |||
It might be different from the selected value in the configuration above, but if so a note appears that a restart is required. | |||
:Required actions: | :'''Required actions:''' An info box appears if the a restart of the packet processing is required. The shown link leads to the page '''Settings → Administration''' where the restart can be triggered. The device itself does not need to be rebooted, only the packet processing must be restarted which usually takes only a few seconds. | ||
An info box appears if the a restart of the packet processing is required. | |||
:Custom remote device SSL certificate: | :'''Custom remote device SSL certificate:''' If a custom SSL certificate is installed on the remote device, you have to upload the public certificate to the master device as well. Otherwise you will get a SSL error during connect to the remote device. Select the PEM certificate and click on '''Install certificate''' to upload it to the device. You can also remove an already installed certificate by clicking on the '''Remove certificate''' button. | ||
If a custom SSL certificate is installed on the remote device, you have to upload the public certificate to the master device as well. Otherwise you will get a SSL error during connect to the remote device. Select the PEM certificate and click on | |||
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|} | |} | ||
The | The '''measurement''' tab show the real-time results of the ongoing measurement. | ||
At the top the current state of the measurement engine and the remote connection is shown. | At the top the current state of the measurement engine and the remote connection is shown. | ||
The measurement status can be | The measurement status can be '''not running''' if it is disabled, '''warming up''' if the engine waits for synchronization with remote device, and '''running''' if it actually measures data. | ||
The | The '''remote client status''' indicates if the connection to the remote device is established. | ||
Since the packet information are gathered real regular capturing from the remote device, the capture connection is visible in the capture section of the remote device and might be stopped there. | Since the packet information are gathered real regular capturing from the remote device, the capture connection is visible in the capture section of the remote device and might be stopped there. | ||
If the measurement connection is stopped or stopped working for other reasons (remote device unavailable, etc), the status box will turn red and a button appears to reconnect to the remote device. | If the measurement connection is stopped or stopped working for other reasons (remote device unavailable, etc), the status box will turn red and a button appears to reconnect to the remote device. | ||
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1. System capture overload: If multiple captures are running in parallel, the CPU might be overloaded. Check the | 1. System capture overload: If multiple captures are running in parallel, the CPU might be overloaded. Check the '''All''' tab in the Capture page to see how many captures are running. | ||
In best case there is only the one capturing connection to the master device. | In best case there is only the one capturing connection to the master device. | ||
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Small non-zero values can be ok, if the first number of monitored flows is much larger. | Small non-zero values can be ok, if the first number of monitored flows is much larger. | ||
'''3.''' Unmonitored flows seen only on | '''3.''' Unmonitored flows seen only on '''master''': | ||
This counter shows the number of IP connections that are only visible at the master device. | This counter shows the number of IP connections that are only visible at the master device. | ||
It means that for those connections no matching client packet has been received. If the master device also sees network traffic that is not routed to the client device, this value can be non-zero. | It means that for those connections no matching client packet has been received. If the master device also sees network traffic that is not routed to the client device, this value can be non-zero. | ||
'''4.''' Unmonitored flows seen only on | '''4.''' Unmonitored flows seen only on '''client''': | ||
This is the same counter as for the master device, but counting the connections on the client device that have not been seen on the master. | This is the same counter as for the master device, but counting the connections on the client device that have not been seen on the master. | ||
Again, if the client device sees traffic that is not routed to the master, it is fine to see non-zero values here. | Again, if the client device sees traffic that is not routed to the master, it is fine to see non-zero values here. | ||
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Below the table, two graphs showing time drift information are visible. | Below the table, two graphs showing time drift information are visible. | ||
The first graph shows the | The first graph shows the '''packet delay'''. It is the time between a matching packet from the master and the client. | ||
This value describes for how long the master device needed to wait to get a matching packet from the client. | This value describes for how long the master device needed to wait to get a matching packet from the client. | ||
This value should always be much lower than the maximum packet delay configured in the path measurement configuration. | This value should always be much lower than the maximum packet delay configured in the path measurement configuration. | ||
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==== FAQ ==== | ==== FAQ ==== | ||
'''1.''' What does the note | '''1.''' What does the note '''Network setup problem detected: Packet modification or complete loss''' means? | ||
This message box appears if flows have been identified for which not a single packet could be seen on both sides. | This message box appears if flows have been identified for which not a single packet could be seen on both sides. | ||