PRTG Manual: SNMP Cisco ASA VPN Connections Sensor

The SNMP Cisco ASA VPN Connections sensor monitors the VPN connections on a Cisco Adaptive Security Appliance via the Simple Network Management Protocol (SNMP).

i_square_cyanFor a detailed list and descriptions of the channels that this sensor can show, see section Channel List.

SNMP Cisco ASA VPN Connections Sensor

SNMP Cisco ASA VPN Connections Sensor

Sensor in Other Languages

  • Dutch: SNMP Cisco ASA VPN Verbindingen
  • French: Cisco ASA connexions VPN (SNMP)
  • German: SNMP Cisco ASA VPN-Verbindungen
  • Japanese: SNMP Cisco ASA VPN 接続数
  • Portuguese: Conexões VPN SNMP Cisco ASA
  • Russian: Подключения SNMP Cisco ASA VPN
  • Simplified Chinese: SNMP Cisco ASA VPN 连接
  • Spanish: Conexiones SNMP Cisco ASA VPN

Remarks

  • This sensor supports the IPv6 protocol.
  • This sensor has a very low performance impact.

Add Sensor

The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the settings that are required to create the sensor. Therefore, you do not see all settings in this dialog. You can change nearly all settings on the sensor's Settings tab after creation.

Basic Sensor Settings

Click the Settings tab of a sensor to change its settings.

Basic Sensor Settings

Basic Sensor Settings

Setting

Description

Sensor Name

Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.

i_round_blueIf the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

i_round_blueThis setting is for your information only. You cannot change it.

Tags

Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.

i_round_blueIt is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

i_round_blueFor performance reasons, it can take some minutes until you can filter for new tags that you added.

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

  • snmpciscoasavpnsensor
  • snmpciscoasavpnconnectionssensor

Priority

Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority (i_priority_1) to the highest priority (i_priority_5).

i_round_blueUsually, a sensor connects to the IP Address/DNS Name of the parent device. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings.

Sensor Display

Sensor Display

Sensor Display

Setting

Description

Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary below a channel gauge on the sensor's Overview tab.

Graph Type

Define how different channels are shown for this sensor:

  • Show channels independently (default): Show a graph for each channel.
  • Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic.
    i_round_redYou cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).

Stack Unit

This setting is only visible if you enable Stack channels on top of each other as Graph Type. Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.

Inherited Settings

By default, all of the following settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.

Credentials for SNMP Devices

Click b_inherited_enabled to interrupt the inheritance.

Credentials for SNMP Devices

Credentials for SNMP Devices

Setting

Description

SNMP Version

Select the Simple Network Management Protocol (SNMP) version for the connection to the target SNMP device:

  • SNMP v1: Use SNMP v1 for the connection. SNMP v1 only offers clear-text data transmission.
    i_round_redSNMP v1 does not support 64-bit counters. This might result in invalid data when you monitor traffic via SNMP.
  • SNMP v2c (recommended): Use SNMP v2c for the connection. SNMP v2c also only offers clear-text data transmission but it supports 64-bit counters.
  • SNMP v3: Use SNMP v3 for the connection. SNMP v3 provides secure authentication and data encryption.
    i_round_redSNMP v3 has performance limitations because of the use of encryption. The main limiting factor is CPU power. Also keep in mind that SNMP v3, unlike SNMP v1 and v2c, does not scale with more CPU power. Because of this limitation, PRTG can only handle a limited number of requests per second so that you can use only a limited number of sensors using SNMP v3. If you see an increase in Interval Delay or Open Requests with the Probe Health sensor, distribute the load over multiple probes. SNMP v1 and SNMP v2c do not have this limitation.

Community String

This setting is only visible if you select SNMP v1 or SNMP v2c (recommended) above. Enter the community string of your device. This is like a clear-text password for simple authentication.

i_round_blueWe recommend that you use the default value.

Authentication Method

This setting is only visible if you select SNMP v3 above. Select the authentication method:

  • MD5: Use message-digest algorithm 5 (MD5) for authentication.
  • SHA: Use Secure Hash Algorithm (SHA) for authentication.

i_round_blueIf you do not want to use authentication but you need SNMP v3, for example, because your device requires context, you can leave the Password field empty. In this case, PRTG uses SNMP_SEC_LEVEL_NOAUTH and it entirely deactivates authentication.

i_round_redThe authentication method you select must match the authentication method of your device.

User Name

This setting is only visible if you select SNMP v3 above. Enter the user name for access to the target SNMP device.

i_round_redThe user name that you enter must match the user name of your device.

Password

This setting is only visible if you select SNMP v3 above. Enter the password for access to the target SNMP device.

i_round_redThe password that you enter must match the password of your device.

Encryption Type

This setting is only visible if you select SNMP v3 above. Select an encryption type:

  • DES: Use Data Encryption Standard (DES) as the encryption algorithm.
  • AES: Use Advanced Encryption Standard (AES) as the encryption algorithm.

i_round_blueNet-SNMP does not support AES-192 and AES-256. They do not have RFC specifications.

i_round_redThe encryption type that you select must match the encryption type of your device.

Encryption Key

This setting is only visible if you select SNMP v3 above. Enter an encryption key. If you provide a key, PRTG encrypts SNMP data packets with the encryption algorithm that you selected above. Enter a string or leave the field empty.

i_round_redThe encryption key that you enter must match the encryption key of your device. If the encryption keys do not match, you do not get an error message.

Context Name

This setting is only visible if you select SNMP v3 above. Enter a context name only if the configuration of the device requires it. Context is a collection of management information that is accessible by an SNMP device. Enter a string.

SNMP Port

Enter the port for the connection to the SNMP target device. Enter an integer value. The default port is 161.

i_round_blueWe recommend that you use the default value.

Timeout (Sec.)

Enter a timeout in seconds for the request. Enter an integer value. The maximum timeout value is 300 seconds (5 minutes).

i_round_blueIf the reply takes longer than this value, the sensor cancels the request and shows a corresponding error message.

Scanning Interval

Click b_inherited_enabled to interrupt the inheritance.

Scanning Interval

Scanning Interval

Setting

Description

Scanning Interval

Select a scanning interval from the dropdown list. The scanning interval determines the amount of time that the sensor waits between two scans. Choose from:

  • 30 seconds
  • 60 seconds
  • 5 minutes
  • 10 minutes
  • 15 minutes
  • 30 minutes
  • 1 hour
  • 4 hours
  • 6 hours
  • 12 hours
  • 24 hours

i_round_blueYou can change the available intervals in the system administration of PRTG Network Monitor.

If a Sensor Query Fails

Select the number of scanning intervals that the sensor has time to reach and to check a device again if a sensor query fails. Depending on the option that you select, the sensor can try to reach and to check a device again several times before the sensor shows the Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows the Warning status. Choose from:

  • Set sensor to down immediately: Set the sensor to the Down status immediately after the first request fails.
  • Set sensor to warning for 1 interval, then set to down (recommended): Set the sensor to the Warning status after the first request fails. If the second request also fails, the sensor shows the Down status.
  • Set sensor to warning for 2 intervals, then set to down: Set the sensor to the Down status only after the third request fails.
  • Set sensor to warning for 3 intervals, then set to down: Set the sensor to the Down status only after the fourth request fails.
  • Set sensor to warning for 4 intervals, then set to down: Set the sensor to the Down status only after the fifth request fails.
  • Set sensor to warning for 5 intervals, then set to down: Set the sensor to the Down status only after the sixth request fails.

i_round_blueSensors that monitor via Windows Management Instrumentation (WMI) always wait at least one scanning interval before they show the Down status. It is not possible to immediately set a WMI sensor to the Down status, so the first option does not apply to these sensors. All other options can apply.

i_round_blueIf you define error limits for a sensor's channels, the sensor immediately shows the Down status. None of the interval options apply.

i_round_blueIf a channel uses lookup values, the sensor immediately shows the Down status. None of the interval options apply.

Schedules, Dependencies, and Maintenance Windows

i_round_blueYou cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.

Schedules, Dependencies, and Maintenance Windows

Schedules, Dependencies, and Maintenance Windows

Setting

Description

Schedule

Select a schedule from the list. You can use schedules to monitor during a certain time span (days or hours) every week. Choose from:

  • None
  • Saturdays
  • Sundays
  • Weekdays
  • Weekdays Eight-To-Eight (08:00 - 20:00)
  • Weekdays Nights (17:00 - 09:00)
  • Weekdays Nights (20:00 - 08:00)
  • Weekdays Nine-To-Five (09:00 - 17:00)
  • Weekends

i_round_blueYou can create schedules, edit schedules, or pause monitoring for a specific time span. For more information, see section Schedules.

Maintenance Window

Select if you want to set up a one-time maintenance window. During a maintenance window, monitoring stops for the selected object and all child objects. They show the Paused status instead. Choose between:

  • Do not set up a one-time maintenance window: Do not set up a one-time maintenance window. Monitoring is always active.
  • Set up a one-time maintenance window: Set up a one-time maintenance window and pause monitoring. You can define a time span for the pause below.

i_round_blueTo terminate an active maintenance window before the defined end date, change the time entry in Maintenance Ends to a date in the past.

Maintenance Begins

This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the one-time maintenance window.

Maintenance Ends

This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the one-time maintenance window.

Dependency Type

Select a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:

  • Use parent: Use the dependency type of the parent object.
  • Select a sensor: Use the dependency type of the parent object. Additionally, pause the current object if a specific sensor is in the Down status or in the Paused status because of another dependency.
  • Master sensor for parent: Make this sensor the master object for its parent device. The sensor influences the behavior of its parent device: If the sensor is in the Down status, the device is paused. For example, it is a good idea to make a Ping sensor the master object for its parent device to pause monitoring for all other sensors on the device in case the device cannot even be pinged. Additionally, the sensor is paused if the parent group is paused by another dependency.

i_round_blueTo test your dependencies, select Simulate Error Status from the context menu of an object that other objects depend on. A few seconds later, all dependent objects are paused. You can check all dependencies under Devices | Dependencies in the main menu bar.

Dependency

This setting is only visible if you enable Select a sensor above. Click b_search_light and use the object selector to select a sensor on which the current object will depend.

Dependency Delay (Sec.)

This setting is only visible if you select Select a sensor above. Define a time span in seconds for the dependency delay.

After the master sensor for this dependency returns to the Up status, PRTG additionally delays the monitoring of the dependent objects by the time span you define. This can prevent false alarms, for example, after a server restart or to give systems more time for all services to start. Enter an integer value.

i_round_redThis setting is not available if you set this sensor to Use parent or to be the Master sensor for parent. In this case, define delays in the parent device settings or in its parent group settings.

Access Rights

Click b_inherited_enabled to interrupt the inheritance.

Access Rights

Access Rights

Setting

Description

User Group Access

Define the user groups that have access to the sensor. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:

  • Inherited: Inherit the access rights settings of the parent object.
  • No access: Users in this user group cannot see or edit the sensor. The sensor neither shows up in lists nor in the device tree.
  • Read access: Users in this group can see the sensor and view its monitoring results. They cannot edit any settings.
  • Write access: Users in this group can see the sensor, view its monitoring results, and edit its settings. They cannot edit its access rights settings.
  • Full access: Users in this group can see the sensor, view its monitoring results, edit its settings, and edit its access rights settings.

i_square_cyanFor more details on access rights, see section Access Rights Management.

Channel List

i_round_blueWhich channels the sensor actually shows might depend on the monitored device, the available components, and the sensor setup.

Channel

Description

Active Email Sessions

The number of active email sessions

Active IPSec Sessions

The number of active Internet Protocol Security (IPsec) sessions

Active L2L Sessions

The number of active LAN-to-LAN (L2L) sessions

Active LB Sessions

The number of active LB sessions

Active Sessions

The total number of active sessions

i_round_blueThis channel is the primary channel by default.

Active SVC Sessions

The number of active switched virtual circuit (SVC) sessions

Active Users

The number of active users

Active WebVPN Sessions

The number of active WebVPN users

Downtime

In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status in percent.

Groups With Active Users

The number of groups with active users

More

i_square_blueKNOWLEDGE BASE

What security features does PRTG include?

What SNMP sensors does PRTG offer?

My SNMP sensors don’t work. What can I do?

Sensor Settings Overview

For more information about sensor settings, see the following sections: