PRTG Manual: Group Settings

Group Name

Enter a meaningful name to identify the group. The name will be shown by default in the device tree and in all alarms.

Status

Choose if monitoring for this group is started or paused. We recommend that you use the default value. You can add additional tags to it, if you like.

• Started: Monitor this group.
• Paused: Pause monitoring for this group. All sensors on all devices in this group will be paused until this setting is changed again.

Parent Tags

Shows Tags that this group inherits from its parent probe. This setting is shown for your information only and cannot be changed here.

Tags

Enter one or more Tags. Confirm each tag by hitting the space, comma, or enter key. You can use tags to group objects and use tag–filtered views later on. Tags are not case sensitive.

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

Priority

Select a priority for the group. This setting determines where the group will be placed in list views. Top priority will be at the top of a list. You can choose from one star (low priority) to five stars (top priority).

Sensor Management

Select which type of auto-discovery you would like to perform for this group. Choose from:

• Manual (no auto-discovery): Do not auto-discover any sensors, only add sensors manually.
• Automatic device identification (standard, recommended): Use a small set of auto-discovery templates. This will scan your LAN and usually create a set of standard sensors on your device.
• Automatic device identification (detailed, may create many sensors): Use an extended set of auto-discovery templates. This will scan your LAN and usually create many sensors on your device.
• Automatic sensor creation using specific device templates: Use specific auto-discovery templates only. Select templates below. This will scan your LAN and add sensors defined in the template.

Device Template(s)

This option is only visible if you enable using specific device templates above. Choose one or more templates by adding a check mark in front of the respective template name. You can also select and deselect all items by using the check box in the table head. PRTG will use the selected templates for auto-discovery on the current device. Choose from:

• ADSL
• Amazon Cloudwatch
• Buffalo TeraStation NAS
• Cisco ASA VPN
• Cisco Device (Generic)
• Dell EqualLogic
• Dell MDI Disk
• DNS Server
• Environment Jacarta
• Environment Poseidon
• FTP Server
• Generic Device (PING only)
• Generic Device (SNMP-enabled)
• Generic Device (SNMP-enabled, Detailed)
• HTTP Web Server
• Hyper V Host Server
• IPMI enabled devices
• Juniper NS Device
• Linux/UNIX Device (SNMP or SSH enabled)
• Mail Server (Generic)
• Mail Server (MS Exchange)
• Microsoft SharePoint 2010
• NAS LenovoEMC
• NAS QNAP
• NAS Synology
• NetApp
• NTP Server
• Printer (HP)
• Printer Generic
• RDP Server
• RMON compatible device
• Server (Compaq/HP agents)
• Server (Dell)
• Server Cisco UCS
• Server IBM
• SonicWall
• SSL Security Check
• Switch (Cisco Catalyst)
• Switch (Cisco IOS Based)
• Switch (HP Procurve)
• UNIX/Linux Device
• UPS Health (APC)
• UPS Health (Generic)
• UPS Health (Liebert)
• VMware ESX / vCenter Server
• Webserver
• Windows (Detailed via WMI)
• Windows (via Remote PowerShell)
• Windows (via WMI)
• Windows IIS (via SNMP)
• XEN Hosts
• XEN Virtual Machines
   

Once the auto-discovery is finished, PRTG will create a new ticket and list the device templates that it used to create new sensors. The ticket will not show templates that were not applied.

Discovery Schedule

Define when PRTG will run the auto-discovery. Choose from:

• Once: Perform auto-discovery only once. PRTG will add new devices and sensors once. If you select this option, you have to start the auto-discovery manually, it will not run automatically.
• Hourly: Perform auto-discovery for new devices and sensors every 60 minutes.
  Please use this option with caution! Frequently executed auto-discoveries might cause performance issues, especially when large network segments are scanned every hour.
• Daily: Perform auto-discovery for new devices and sensors every 24 hours. The first auto-discovery will run immediately, all other discoveries will start at the time defined in the Auto-Discovery Settings section of the System Administration—Monitoring settings.
• Weekly: Perform auto-discovery for new devices and sensors every 7 days. The first auto-discovery will run immediately, all other discoveries will start at the time defined in the Auto-Discovery Settings section of the System Administration—Monitoring settings.

The Discovery Schedule will be set to Once on all devices created by the scheduled auto-discovery for performance reasons.

IP Selection Method

Define how you want to define the IP range for auto-discovery. Choose from:

• Class C base IP with start/end (IPv4): Define an IPv4 class C address range.
• List of individual IPs and DNS names (IPv4): Enter a list of individual IPv4 addresses or DNS names.
• IP and subnet (IPv4): Enter an IPv4 address and subnet mask.
• IP with octet range (IPv4): Enter an IPv4 address range for every IP octet individually. With this, you can define very customizable IP ranges.
• List of individual IPs and DNS names (IPv6): Enter a list of individual IPv6 addresses or DNS names.
• Use computers from the Active Directory (maximum 1000 computers): Search in the Active Directory for computers to perform auto-discovery.
  Define your Active Directory domain in advance in the system administration. See section System Administration—Core & Probes.

Only subnets with up to 65,536 IP addresses can be discovered! If you define a range with a higher number of addresses, discovery will stop before it is completed.

IPv4 Base

This field is only visible if you select Class C network detection above. Enter a class C network as IP base for the auto-discovery. Enter the first three octets of an IPv4 IP address, for example, 192.168.0

IPv4 Range Start

This field is only visible if you select Class C network detection above. Enter the IP octet of the class C network specified above from which PRTG will start the auto-discovery. This will complete the IP base above to an IPv4 address. For example, enter 1 to discover from 192.168.0.1.

IPv4 Range End

This field is only visible if you select Class C network detection above. Enter the IP octet of the class C network specified above at which PRTG will stop the auto-discovery. This will complete the IP base above to an IPv4 address. For example, enter 254 to discover up to 192.168.0.254.

IPv4/DNS Name List
IPv6/DNS Name List

This field is only visible if you select the IP list option above. Enter a list of IP addresses or DNS names that the auto-discovery will scan. Enter each address in a separate line.

IPv4 and Subnet (IPv4)

This field is only visible if you select the IP and subnet option above. Enter an expression in the format address/subnet, for example, 192.168.3.0/255.255.255.0. You can also use the short form like 192.168.3.0/24 in this example. PRTG will scan the complete host range (without network and broadcast address) defined by the IP address and the subnet mask.

IP with Octet Range

This field is only visible if you select the octet range option above. Enter an expression in the format a1.a2.a3.a4, where a1, a2, a3, and a4 are each a number between 0-255, or a range with two numbers and a hyphen like 1-127. All permutations of all ranges are calculated. For example, 10.0.1-10.1-100 results in 1,000 addresses that PRTG will scan during auto-discovery.

Organizational Unit

This field is only visible if you select Active Directory above. Enter an organizational unit (OU) to restrict the Active Directory search to computers that are part of this OU. For top-level OUs, use the distinguished name (DN) format without the leading OU= and without the domain components (DC). If you leave this field empty, there will not be any restriction.

Example:

• For the DN OU=Domain Controllers,DC=example,DC=com, enter only Domain Controllers.

Make sure that the OU contains computer accounts. If the OU is empty, you will receive an error message.

If you have sub-OUs, use the DN format without the leading OU= and without the domain components (DC).

Examples:

• For the DN OU=webserver,OU=production,DC=example,DC=com, enter only webserver,OU=production.
• For the DN OU=intranet,OU=webserver,OU=production,DC=example,DC=com, enter only intranet,OU=webserver,OU=production.

Make sure that the OU contains computer accounts. If the OU is empty, you will receive an error message.

Do not enter the domain components. PRTG automatically uses the domain components from the domain name you entered in System Administration—Core & Probes.

Name Resolution

Define how to monitor newly discovered devices. This affects only new devices. The setting for existing devices will remain unchanged. Depending on your selection, the IP Address/DNS Name field of an added device shows the DNS name or IP address that PRTG uses to access the target device. Choose between:

• Use DNS names (recommended): Monitor newly discovered devices via their DNS names (if available).
• Use IP addresses: Monitor newly discovered devices via their IP addresses.

We recommend that you use the default value.

This setting does not affect how PRTG shows the devices in the device tree.

Device Rescan

Define if you want to add devices that already exist in your PRTG installation also to the currently selected group. Choose between:

• Skip auto-discovery for known devices/IPs (recommended): Do not re-scan known devices or IP addresses, only add devices with new IPs or DNS names when auto-discovering. PRTG will not add devices that are already included elsewhere in your configuration, for example, in other groups.
• Perform auto-discovery for known devices/IPs: Re-scan devices with known IP addresses with every auto-discovery. This option will add devices that already exist in other groups also to this group and runs the auto-discovery on the newly added devices.
  The auto-discovery will not run on devices that already exist in this group. If you want to run the auto-discovery for an existing device, you have to start the auto-discovery on this device.

We recommend that you use the default value.

In certain cases, the IP resolution may not work and might result in a device not being added if it has the same local IP address as in another LAN.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Location (for Geo Maps)

When you want to use Geo Maps, enter a location in the first line. Geographical maps will then display objects (devices, groups) with a flag, showing the current status using a color code similar to the sensor status icons (green - yellow - orange - red). You can enter a full postal address, city and country only, or latitude and longitude. It is possible to enter any text before, between, and after the coordinates, PRTG will parse latitude and longitude automatically, for example: 49.452778 11.077778 or enter 49.452778 any 11.077778 text

A minus sign (–) in the first line will hide an object from geo maps. In this case, you can enter location information in line two and following.

You can define a specific label for each location: enter a string denoting the label in the first line and provide geo coordinates in the second line. This geo marker will then show the object with the label in the PRTG geo map.

The preview map will always have a road map layout regardless of the map layout you set in User Interface.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Domain or Computer Name

Define the authority for Windows access. This is used for Windows Management Instrumentation (WMI) and other Windows sensors. If you want to use a Windows local user account on the target device, enter the computer name here. If you want to use a Windows domain user account (recommended), enter the (Active Directory) domain name here. If not explicitly defined, PRTG will automatically add a prefix in order to use the NT LAN Manager (NTLM) protocol. Do not leave this field empty.

User

Enter the username for Windows access. Usually, you will use credentials with administrator privileges.

Password

Enter the password for Windows access. Usually, you will use credentials with administrator privileges.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

User

Enter a login name for the access via SSH and WBEM. Usually, you will use credentials with administrator privileges.

Login

Define the authentication method to use for login. Choose between:

• Login via Password: Provide a password for login. Enter below.
• Login via Private Key: Provide a private key for authentication.
  PRTG can only handle keys in OpenSSH format that are not encrypted. You cannot use password-protected keys here. In the text field, paste the entire private key, including the "BEGIN" and "END" lines. Please make sure the according public key is provided on the target machine. For details, see section Monitoring via SSH.

Password

This field is only visible if you select password login above. Enter a password for the Linux access via SSH and WBEM. Usually, you will use credentials with administrator privileges.

Private Key

This field is only visible if you select private key login above. Paste a private key into the field (OpenSSH format, unencrypted). Usually, you will use credentials with administrator privileges.

If you do not insert a private key for the first time, but change the private key, you need to restart your PRTG core server service in order for the private key change to take effect! For details, see section Monitoring via SSH.

For WBEM Use Protocol

Define the protocol to use for WBEM. This setting is only relevant if you use WBEM sensors. Choose between:

• HTTP: Use an unencrypted connection for WBEM.
• HTTPS: Use an SSL-encrypted connection for WBEM.

For WBEM Use Port

Define the port to use for WBEM. This setting is only relevant if you use WBEM sensors. Choose between:

• Set automatically (port 5988 or 5989): Use one of the standard ports, depending on whether you choose unencrypted or encrypted connection above.
• Set manually: Use a custom port. Define below.

WBEM Port

This setting is only visible if you enable manual port selection above. Enter the WBEM port number.

SSH Port

Enter the port number to use for SSH connections.

By default, PRTG uses this setting automatically for all SSH sensors, unless you define a different port number in the sensor settings.

SSH Rights Elevation

Define the rights that you want to use to execute the command on the target system. Choose from:

• Run the command as the user connecting (default): Use the rights of the user who establishes the SSH connection, as defined above.
• Run the command as another user using 'sudo' (with password): Use the rights of another user with a password required for sudo to run commands on the target device, for example, as root user.
• Run the command as another user using 'sudo' (without password): Use the rights of another user without a password required for sudo to run commands on the target device, for example, as root user.
• Run the command as another user using 'su': Use the rights of another user with su to run commands on the target device.

Target User

This field is only visible if you choose sudo or su above. Enter a username to run the specified command as a user other than root. If you leave this field empty, you will run the command as root. Ensure you set the Linux password even if you use a public or private key for authentication. This is not necessary if the user is allowed to execute the command without a password.

Password

This field is only visible if you choose to run the commands using su or sudo with password above. Enter the password for the specified target user.

SSH Engine

Select the method you want to use to access data with SSH sensors. We strongly recommend that you keep the default engine! For now, you still can use the legacy mode to ensure compatibility with your target systems. Choose between:

• Default (recommended): This is the default monitoring method for SSH sensors. It provides the best performance and security.
• Compatibility Mode (deprecated): Try this legacy method only if the default mode does not work on a target device. The compatibility mode is the SSH engine that PRTG used in previous versions and is deprecated. We will remove this legacy option soon, so please try to get your SSH sensors running with the default SSH engine.

You can also individually select the SSH engine for each SSH sensor in the sensor settings.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

User

Enter a login name for access to VMware and Xen servers. Usually, you will use credentials with administrator privileges.

Password

Enter a password for access to VMware and Xen servers. Usually, you will use credentials with administrator privileges.

Single Sign-On (SSO) passwords for vSphere do not support special characters. See the manual sections for VMware sensors for details.

VMware Protocol

Define the protocol used for the connection to VMware and XenServer. Choose between:

• HTTPS (recommended): Use an SSL-encrypted connection to VMware and Xen servers.
• HTTP: Use an unencrypted connection to VMware and Xen servers.

Session Pool

Define if you want to use session pooling for VMware sensors. Choose between:

• Reuse session for multiple scans (recommended): Select this option to use session pooling. With session pooling, a VMware sensor uses the same session as created in advance to query data and does not need to log in and out for each sensor scan. We recommend that you choose this option because it reduces network load and log entries on the target device, resulting in better performance.
• Create a new session for each scan: If you select this option and disable session pooling, a VMware sensor has to log in and out for each sensor scan. We recommend that you use the session pooling option above for better performance.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

SNMP Version

Select the SNMP version for the device connection. Choose from:

• v1: Use the simple v1 protocol for SNMP connections. This protocol only offers clear-text data transmission, but it is usually supported by all devices.
  SNMP v1 does not support 64-bit counters.
  This may result in invalid data when monitoring traffic via SNMP.
• v2c (recommended): Use the more advanced v2c protocol for SNMP connections. This is the most common SNMP version. Data is still transferred as clear-text, but it supports 64-bit counters.
• v3: Use the v3 protocol for SNMP connections. It provides secure authentication and data encryption.

When using SNMP v3 you can only monitor a limited number of sensors per second due to internal limitations. The limit is somewhere between 1 and 50 sensors per second (depending on the SNMP latency of your network). This means that using an interval of 60 seconds limits you to between 60 and 3000 SNMP v3 sensors for each probe. If you experience an increased Interval Delay or Open Requests with the Probe Health sensor, distribute the load over multiple probes. SNMP v1 and v2 do not have this limitation.

Community String

This setting is only visible if you select SNMP version v1 or v2c above. Enter the community string of your devices. This is a kind of "clear-text password" for simple authentication. We recommend that you use the default value.

Authentication Type

This setting is only visible if you select SNMP version v3 above. Choose between:

• MD5: Use Message-Digest Algorithm 5 (MD5) for authentication.
• SHA: Use Secure Hash Algorithm (SHA) for authentication.

The type you choose must match the authentication type of your device.

If you do not want to use authentication, but you need SNMP v3, for example, because your device requires context, you can leave the field Password empty. In this case, SNMP_SEC_LEVEL_NOAUTH is used and authentication deactivated entirely.

User

This setting is only visible if you select SNMP version v3 above. Enter a username for secure authentication. This value must match the username of your device.

Password

This setting is only visible if you select SNMP version v3 above. Enter a password for secure authentication. This value must match the password of your device.

Encryption Type

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

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

AES-192 and AES-256 are not supported by Net-SNMP. They lack RFC specification.

The type that you choose must match the encryption type of your device.

Data Encryption Key

This setting is only visible if you select SNMP version v3 above. Enter an encryption key here. If you provide a key in this field, SNMP data packets are encrypted using the encryption algorithm selected above, which provides increased security. The key that you enter here must match the encryption key of your device.

If the key you enter in this field does not match the key configured on the target SNMP device, you will not get an error message about this! Please enter a string or leave the field empty.

Context Name

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

SNMP Port

Enter the port for the SNMP communication. We recommend that you use the default value.

SNMP Timeout (Sec.)

Enter a timeout in seconds for the request. Please enter an integer value. If the reply takes longer than the value you enter here, the request is aborted and an error message is triggered. The maximum timeout value is 300 seconds (5 minutes).

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

The settings you define in this section apply to the following sensor types:

• ADO SQL v2 sensor
• Microsoft SQL v2 sensor
• MySQL v2 sensor
• Oracle SQL v2 sensor
• PostgreSQL sensor

Port for Databases

Define which ports PRTG will use for connections to the monitored databases. Choose between:

• Set automatically (default port, recommended): PRTG automatically determines the type of the monitored database and uses the corresponding default port to connect. See below for a list of default ports.
• Define one custom port valid for all database sensors: Choose this option if your database management systems do not use the default ports. Define the port for database connections manually below. If you choose this option, PRTG will use the custom port for all database sensors.

If you choose the automatic port selection, PRTG uses the following default ports:

• Microsoft SQL: 1433
• MySQL: 3306
• Oracle SQL: 1521
• PostgreSQL: 5432

Custom Database Port

Enter the number of the port that PRTG will use for database connections. Please enter an integer value.

All database sensors on this device will use this port to connect.

Authentication Mode

Select the authentication method for the connection to the SQL database. Choose between:

• Windows authentication with impersonation: If you select this option, PRTG uses the Windows credentials as defined in the particular device settings for the database connection.
  The user whose credentials are used needs to have permission to log on to the system on which the PRTG probe with a database sensor runs. This is required for the impersonation.
• SQL server authentication: Choose this option if you want to use explicit credentials for database connections.

User

This field is only visible if you select SQL server authentication above. Enter the username for the database connection.

Password

This field is only visible if you select SQL server authentication above. Enter the password for the database connection.

Timeout (Sec.)

Enter a timeout in seconds for the request. Please enter an integer value. If the reply takes longer than this value defines, the sensor cancels the request and triggers an error message. The maximum timeout value is 300 seconds (5 minutes).

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Access Key

Enter your Amazon Web Services (AWS) access key. Please see the corresponding Amazon CloudWatch sensor documentation to learn more about the rights that are required for querying AWS CloudWatch metrics.

Secret Key

Enter your Amazon Web Services (AWS) secret key. Please see the corresponding Amazon CloudWatch sensor documentation to learn more about the rights that are required for querying AWS CloudWatch metrics.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

User Credentials

Choose if you want to connect without credentials, or define credentials for the connection.

• None: Connect without credentials.
• Username/Password: Define credentials for the connection.

Username

This field is only visible if you select Username/Password above. Enter the username for access to the MQTT broker.

Password

This field is only visible if you select Username/Password above. Enter the password for access to the MQTT broker.

Port

Enter the port number for MQTT connections. Usually this is port 1883 for unencrypted connections, and port 8883 when using TLS.

Transport-Level Security

Choose if you want to use encryption and define required certificates.

• Don't use encryption: Do not use TLS encryption.
• Use TLS encryption: Use TLS encryption.

Server Authentication

This field is only visible if you select Use TLS encryption above. Choose if you want to use a certificate for server authentication.

• Disable server authentication: Do not use a certificate for server authentication.
• Enable server authentication: Use a certificate for server authentication.

CA Certificate

Copy the Certificate Authority’s (CA) certificate for verifying the MQTT server and paste it here.

The certificate must be in PEM format.

Client Authentication

This field is only visible if you select Use TLS encryption above. Choose if you want to use a certificate for client authentication.

• Disable client authentication: Do not use a certificate for client authentication.
• Enable client authentication: Use a certificate for client authentication.

Client Certificate

Copy the certificate that you created for authenticating the sensor against the server and paste it here.

The certificate must be in PEM format.

Client Key

Enter the client key for authentication against the server.

The client key must be encrypted using the Client Key Password.

Client Key Password

Enter the password for the client key certificate.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

When experiencing problems while monitoring via Windows sensors, you can set some compatibility options for troubleshooting.

Preferred Data Source

Define the method Windows sensors will use to query data. This setting is valid only for hybrid sensors offering performance counter and Windows Management Instrumentation (WMI) technology. The setting will be ignored for all other sensors! Choose from:

• Performance Counters and fallback to WMI: Try to query data via performance counters. If this is not possible, establish a connection via WMI.

• Performance Counters only: Query data via performance counters only. If this is not possible, a sensor will return no data.

• WMI only (recommended): Query data via WMI only. If this is not possible, a sensor will return no data. In current PRTG versions, this is our recommendation to achieve best performance and stability.

Timeout Method

Specify the time the sensor will wait for the return of its WMI query before aborting it with an error message. Choose between:

• Use 1.5x scanning interval (recommended): Use a default of one and a half times the scanning interval set for the sensor (see the Scanning Interval settings below).
• Set manually: Enter a timeout value manually.

We recommend that you use the default value. Only if you experience ongoing timeout errors, try increasing the timeout value.

Timeout Value (Sec.)

This field is only visible if the manual timeout method is selected above. Enter the time the sensor will wait for the return of its WMI query before aborting with an error message. Please enter an integer value. The maximum value is 900 seconds (15 minutes).

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

When experiencing problems while monitoring via Simple Network Management Protocol (SNMP) sensors, you can set some compatibility options for troubleshooting.

SNMP Delay (ms)

Add a time in milliseconds that will be waited between two SNMP requests. This can help increase device compatibility. Please enter an integer value. We recommend that you use the default value. If you experience SNMP connection failures, please increase the delay. You can define a delay between 0 and 100, higher delays are not supported and will be discarded.

Failed Requests

Define if an SNMP sensor will try again after a request fails.

• Retry (recommended): Try again if an SNMP request fails. This can help prevent false error messages due to temporary timeout failures.
• Do not retry: Do not retry if an SNMP request fails. With this setting enabled, an SNMP sensor will be set to error status earlier.

Overflow Values

Define how PRTG will handle overflow values. Some devices do not handle internal buffer overflows correctly. This can cause false peaks.

• Ignore overflow values: Ignore overflow values and do not include them in the monitoring data.
• Handle overflow values as valid results: Regard all overflow values as regular data and include them in the monitoring data.

We recommend that you use the default value.

If you experience problems because of strange peaks in your data graphs, change this option. Peaks might indicate that the monitored device resets counters without an overflow. PRTG interprets such behavior as overflow that results in data peaks. Choose the option Ignore overflow values in this case. For more details, see the Knowledge Base: What is the Overflow Values setting in the SNMP Compatibility Options?

Zero Values

Define how PRTG will handle zero values. Some devices send incorrect zero values. This can cause false peaks.

• Ignore zero values for delta sensors (recommended): Ignore zero values and do not include them in the monitoring data.
• Handle zero values as valid results for delta sensors: Regard all zero values as regular data and include them in the monitoring data.

We recommend that you use the default value. If you experience problems, change this option.

32-bit/64-bit Counters

Define which kind of traffic counters PRTG will search for on a device.

• Use 64-bit counters if available (recommended): The interface scan will use 64-bit traffic counters, if available. This can avoid buffer overflows in the devices.
• Use 32-bit counters only: The interface scan will always use 32-bit traffic counters, even if 64-bit counters are available. This can lead to more reliable monitoring for some devices.

We recommend that you use the default value. If you experience problems, change this option.

Request Mode

Define which kind of request method PRTG uses for SNMP sensors.

• Use multi get (recommended): Bundle multiple SNMP requests into one request.
• Use single get: Use one request for each SNMP value. This can increase compatibility with older devices.

We recommend that you use the default value. If you experience problems, change this option.

PRTG uses paging for SNMP requests. This means that if a sensor has to query more than 20 OIDs, it will automatically poll the OIDs in packages of 20 OIDs each per request.

Walk Mode

Define which kind of SNMP walk PRTG uses for SNMP sensors.

• Use GETBULK requests (recommended): Request the next x OIDs (default 10, dynamic based on response size) in one SNMP request.
• Use GETNEXT requests: Request one OID at a time. This can increase compatibility with older devices or devices that have insufficient SNMP BULKWALK support.

Only works with devices that support SNMP version v2c or higher. Ensure you set the correct SNMP Version in the Credentials for SNMP Devices settings of the parent device or inherit it from objects higher in the hierarchy.

Port Name Template

Define how the name of SNMP sensors created on a device will be put together. Enter a template using several variables. When adding new sensors, PRTG scans the interface for available counters at certain OIDs. At each OID usually several fields are available with interface descriptions. They are different for every device and OID. PRTG will use the information in these fields to name the sensors. If a field is empty or not available, an empty string is added to the name. By default, ([port]) [ifalias] is set as port name template, which will create a name such as (001) Ethernet1, for example. You can use any field names available at a certain OID of your device, among which are:

• [port]: The port number of the monitored interface.
• [ifalias]: The 'alias' name for the monitored interface as specified by a network manager, providing a non-volatile handling.
• [ifname]: The textual name of the monitored interface as assigned by the local device.
• [ifdescr]: A textual string containing information about the monitored device or interface, for example, manufacturer, product name, or version.
• [ifspeed]: An estimate of the monitored interface's current bandwidth (Kbit/s).
• [ifsensor]: The type of the sensor, this is SNMP Traffic or SNMP RMON. This is useful to differentiate between your SNMP Traffic and SNMP RMON sensors.

Combine them as you like to obtain suitable sensor names.

For more information about SNMP sensor names, see the Knowledge Base: How can I change the defaults for names automatically generated for new SNMP sensors?

Port Name Update

Define how PRTG will react if you change port names in your physical device (for example, a switch or router). Choose between:

• Keep port names (use this if you edit the names in PRTG): Do not automatically adjust sensor names. This is the best option if you want to change names in PRTG manually.

• Automatic sensor name update if name changes in device: If PRTG detects changes of port names in your physical device, it will try to automatically adjust sensor names accordingly.

For more information about automatic updates of names, see the Knowledge Base: Automatically update port name and number for SNMP Traffic sensors when the device changes them

Port Identification

Define which field will be used for SNMP interface identification. Choose from:

• Automatic (recommended): Tries the ifAlias field first to identify an SNMP interface and then ifDescr.
  ifName will not be tried automatically.
• Use ifAlias: For most devices, ifAlias is the best field to get unique interface names.
• Use ifDescr: Use this option if the port order of your device changes after a reboot, and if there is no ifAlias field available. For example, this is the best option for Cisco ASA devices.
  When using this option, it is important that your device returns unique interface names in the ifDescr field.
• Use ifName: You can also use this option if there is no unique ifAlias available.
  When using this option, it is important that your device returns unique interface names in the ifName field.
• No Port Update: Use this option to disable automatic port identification.

Start Interface Index

For SNMP Traffic sensors, define at which index PRTG will start to query the interface range during sensor creation. Use 0 for automatic mode. We recommend that you use the default value.

End Interface Index

For SNMP Traffic sensors, define at which index PRTG will stop to query the interface range during sensor creation. Use 0 for automatic mode. We recommend that you use the default value.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

The proxy settings determine how a sensor connects to a given URL. You can enter data for an HTTP proxy server that sensors will use when connecting via HTTP or HTTPS.

This setting affects monitoring only and determines the behavior of HTTP sensors. To change proxy settings for the core server, see section System Administration—Core & Probes.

The SSL Certificate sensor and the SSL Security Check sensor do not support HTTP proxies, but you can configure connections via SOCKS proxies in their sensor settings.  

Name

Enter the IP address or DNS name of the proxy server to use. If you leave this field empty, no proxy will be used.

Port

Enter the port number of the proxy. Often, port 8080 is used. Please enter an integer value.

User

If the proxy requires authentication, enter the username for the proxy login.

Only basic authentication is available! Please enter a string or leave the field empty.

Password

If the proxy requires authentication, enter the password for the proxy login.

Only basic authentication is available! Please enter a string or leave the field empty.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Scanning Interval

Select a scanning interval (seconds, minutes, or hours) from the list. The scanning interval determines the time the sensor waits between two scans. You can change the available intervals in the system administration on PRTG on premises installations.

If a Sensor Query Fails

Define the number of scanning intervals that a sensor has time to reach and check a device again in case a sensor query fails. The sensor can try to re-reach and check a device several times, depending on the option you select here, before it will be set to a Down status. This helps you avoid false alarms if the monitored device has only temporary issues. For previous scanning intervals with failed requests, the sensor will show a Warning status. Choose from:

• Set sensor to down immediately: The sensor will show an error immediately after the first failed request.
• Set sensor to warning for 1 interval, then set to down (recommended): After the first failed request, the sensor will show a warning status. If the following request also fails, the sensor will show an error.
• Set sensor to warning for 2 intervals, then set to down: Show an error status only after three consecutively failed requests.
• Set sensor to warning for 3 intervals, then set to down: Show an error status only after four consecutively failed requests.
• Set sensor to warning for 4 intervals, then set to down: Show an error status only after five consecutively failed requests.
• Set sensor to warning for 5 intervals, then set to down: Show an error status only after six consecutively failed requests.

Sensors that monitor via Windows Management Instrumentation (WMI) always wait at least one scanning interval until they show an error. It is not possible to set a WMI sensor to Down immediately, so the first option will not apply to these sensor types. All other options can apply.

If a sensor has defined error limits for channels, it will always show a Down status immediately, so no "wait" option will apply.

If a channel uses lookup values, it will always show a Down status immediately, so no "wait" options will apply.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Scanning Distribution

This box is only visible if you run a PRTG cluster. Sometimes you want to exclude a certain node from monitoring the sensors running on this probe, group, or device, for example, if a device is not reachable from every node configured in your cluster. In the list of cluster nodes, select the nodes that will not be included in sensor scans. By default, this setting is inherited to all objects underneath.

Inheritance for schedules, dependencies, and maintenance windows cannot be interrupted; the according settings from the parent objects will always be active. However, you can define additional settings here. They will be active in parallel to the parent objects' settings.

Schedule

Select a schedule from the list. Schedules can be used to pause monitoring for a certain time span (days, hours) throughout the week. You can create new schedules and edit existing ones in the account settings.

Schedules are generally inherited. New schedules will be added to existing ones, so all schedules are active.

Maintenance Window

Specify if you want to set-up a one-time maintenance window. During a maintenance window this object and all child objects will not be monitored. They will enter a paused state then. Choose between:

• Not set (monitor continuously): No maintenance window will be set.
• Set up a one-time maintenance window: Pause monitoring within a maintenance window.

To terminate a current maintenance window before the defined end date, you can change the time in Maintenance Ends field to a date in the past.

Maintenance Begins

This field is only visible if maintenance window is enabled above. Use the date time picker to enter the start date and time of the maintenance window.

Maintenance Ends

This field is only visible if maintenance window is enabled above. Use the date time picker to enter the end date and time of the maintenance window.

Dependency Type

Define a dependency type. Dependencies can be used to pause monitoring for an object depending on the status of another. You can choose between:

• Use parent: Pause the current object if its parent object is in a Down status, or if it is paused by another dependency.

• Select object: Pause the current object if its parent object is in a Down status, or if it is paused by another dependency. Additionally, pause the current object if a specific other object in the device tree is in a Down status, or if it is paused by another dependency. Select below.

You do not trigger a status change by dependency if you manually pause a master object or if you pause it by schedule.

Testing your dependencies is easy! Simply choose Simulate Error Status from the context menu of an object that other objects depend on. A few seconds later, all dependent objects should be paused. You can check all dependencies in your PRTG installation by selecting Devices | Dependencies from the main menu bar.

Dependency

This field is only visible if the select object option is enabled above. Click on the reading-glass symbol and use the object selector to choose an object on which the current object will be dependent.

Dependency Delay (Sec.)

This field is only visible if you select an object other than the parent as dependency type. Define a time span in seconds for dependency delay.

After the master object for this dependency comes back to an Up status, monitoring of the depending objects will be additionally delayed by the defined time span. This can help avoid false alarms, for example, after a server restart, by giving systems more time for all services to start up. Please enter an integer value.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

User Group Access

Define which user group(s) will have access to the object you're editing. A table with user groups and types of access rights is shown. It contains all user groups from your setup. For each user group, you can choose from the following access rights:

• Inherited: Use the access rights settings of the parent object.
• None: Users in this group cannot see or edit the object. The object neither shows up in lists nor in the device tree. Exception: If a child object is visible to the user, the object is visible in the device tree, though not accessible.
• Read: Users in this group can see the object and review its monitoring results.
• Write: Users in this group can see the object, review its monitoring results, and edit the object's settings. They cannot edit access rights settings.
• Full: Users in this group can see the object, review its monitoring results, edit the object's settings, and edit access rights settings.

You can create new user groups in the System Administration—User Groups settings. To automatically set all objects further down in the hierarchy to inherit this object's access rights, set a check mark for the Revert children's access rights to inherited option.

For more details on access rights, see section User Access Rights.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Channel Unit Types

For each type of sensor channel, define the unit in which data is displayed. If defined on probe, group, or device level, these settings can be inherited to all sensors underneath. You can set units for the following channel types (if available):

• Bandwidth
• Memory
• Disk
• File
• Custom

Custom channel types can be set on sensor level only.

Click to disrupt the inheritance. See section Inheritance of Settings for more information.

Unusual Detection

Define if you want to benefit from unusual detection for sensors. You can configure the behavior of unusual detection (or disable it completely) in the system settings. Choose between:

• Enabled: Activate unusual detection for this object and, by default, for all objects underneath in the hierarchy of the device tree. Sensors affected by this setting will turn to orange color (unusual sensor status) if PRTG detects unusual activity.
• Disabled: Do not activate unusual detection. PRTG will ignore unusual values for sensors affected by this setting. These sensors will not show an unusual sensor status.

Similar Sensors Detection

Define if you want to activate Similar Sensors analysis. You can configure the depth of analysis of similar sensors detection (or disable it completely) in the system settings. Choose between:

• Enabled: Activate similar sensors detection for this object and, by default, for all objects underneath in the hierarchy of the device tree. PRTG considers all sensors affected by this setting during similarity analysis.
• Disabled: Do not activate similar sensors detection. PRTG will not consider sensors affected by this setting during similarity analysis.

System Information

Define if you want to retrieve and show System Information for your devices. Choose between:

• Enabled: Activate the system information feature for this object and, by default, for all objects underneath in the hierarchy of the device tree.
• Disabled: Do not activate system information.

System Information is enabled by default. To retrieve the data, PRTG will automatically use Credentials for Windows Systems and Credentials for SNMP Devices as defined in the device settings or as inherited from a parent object like the Root group. Please consider this when you monitor devices outside the local network, especially when using SNMP v1 or v2c that do not provide encryption.

This setting is not available on the Hosted Probe of a PRTG hosted by Paessler instance.

Sensor Limit

This setting allows the administrator to set a limit for the maximum number of sensors in this group. Subgroups are also included in this limitation. If the amount of sensors exceeds the limitation, surplus sensors will be paused. This is of special interest for a Managed Service Provider (MSP). Choose between:

• Allow unlimited number of sensors: Do not limit the number of sensors for this group. Any number of sensors can be added to this group and its subgroups.
• Limit number of sensors in this group: Enable a limitation for the number of sensors in this group. Only a defined number of sensors can monitor in this group and its subgroups.

Maximum Number of Sensors

This field is only visible if you enable limitation above. Define how many sensors are allowed in this group and its subgroups. Sensors that exceed this group sensor limit will be paused. Please enter an integer value.

Sensors in paused status count for this group limit as well (for example, manually paused sensors, sensors paused by dependency or schedule), but not for the number of available sensors in your license.

Manually paused sensors will override the sensor message "exceeds group sensor limit".