PRTG Manual: Group Settings

Group Name

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

Status

Select if monitoring for this group is started or paused. We recommend that you use the default value.

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

Parent Tags

Show 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 with a comma, the Spacebar key, or the 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 parentheses (()) or angle brackets (<>).

Priority

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

Auto-Discovery Level

Define the level of detail for the PRTG auto-discovery:

• No auto-discovery: Select this option if you want to create devices and sensors only manually.

• Standard auto-discovery (recommended): Create a set of standard sensors for standard monitoring. This option works fine for most installations.
• Detailed auto-discovery: Create all standard sensors and additional sensors from detailed variants of device templates. As a result, you may get many sensors. This option is suitable for small network segments and whenever you want to monitor the maximum number of sensors available.
• Auto-discovery with specific device templates: Customize the auto-discovery and select or combine standard, detailed, and custom device templates. From the list below, select one or more templates.

Auto-discoveries can be resource-intensive and are primarily intended for devices on the same network as your probes.

Device Templates

This option is only visible if you enable using specific device templates above. Select one or more templates by adding a check mark in front of the respective template name. You can also select all items or cancel the selection by using the check box in the table header. PRTG uses 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 creates a new ticket and lists the device templates that it used to create new sensors.

Schedule

Define when PRTG runs the auto-discovery:

• Once: Perform the auto-discovery only once. PRTG adds new devices and sensors once. If you select this option, you have to start the auto-discovery manually.
• Hourly: Perform the auto-discovery for new devices and sensors every 60 minutes.
  Use this option with caution! Frequently executed auto-discoveries might cause performance issues, in particular when large network segments are scanned every hour.
• Daily: Perform the auto-discovery for new devices and sensors every 24 hours. The first auto-discovery runs immediately, all other discoveries start at the time defined in the Auto-Discovery settings section under Setup | System Administration | Monitoring.
• Weekly: Perform auto-discovery for new devices and sensors every 7 days. The first auto-discovery runs immediately, all other discoveries start at the time defined in the Auto-Discovery settings section under Setup | System Administration | Monitoring.

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

IP Selection Method

Specify how you want to define the IP range for auto-discovery:

• 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 Domain Name System (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 the auto-discovery.
  Specify your Active Directory domain in advance in the system administration. See section System Administration—Core & Probes.

PRTG can only discover subnets with up to 65,536 IP addresses. If you define a range with a higher number of addresses, the discovery stops before it is completed.

IPv4 Base

This field is only visible if you enable Class C base IP with start/end (IPv4) 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 enable Class C base IP with start/end (IPv4) above. Enter the IP octet of the class C network specified above from which PRTG starts the auto-discovery. This completes 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 enable Class C base IP with start/end (IPv4) above. Enter the IP octet of the class C network specified above at which PRTG stops the auto-discovery. This completes 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 List of individual IPs and DNS names option above. Enter a list of IP addresses or DNS names that the auto-discovery scans. Enter each address in a separate line.

IPv4 and Subnet (IPv4)

This field is only visible if you enable IP and subnet (IPv4) 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 scans 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 enable IP with octet range (IPv4) above. Enter an expression in the format a1.a2.a3.a4, where a1, a2, a3, and a4 each are 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 scans during the auto-discovery.

Organizational Unit

This field is only visible if you enable Use computers from the Active Directory (maximum 1000 computers) 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 OU= and without the domain components (DCS). If you leave this field empty, there are not any restrictions.

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 receive an error message.

If you have sub-OUs, use the DN format without the leading OU= and without the DCs.

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 receive an error message.

Do not enter the domain components. PRTG automatically uses the domain components from the domain name you entered under Setup | System Administration | Core & Probes.

Name Resolution

Define how to monitor newly discovered devices. This affects only new devices, the setting for existing devices remains 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 to the currently selected group as well:

• Skip auto-discovery for known devices/IPs (recommended): Do not rescan known devices or IP addresses, only add devices with new IPs or DNS names. PRTG does not add devices that are already included elsewhere in your configuration, for example, in other groups.
• Perform auto-discovery for known devices/IPs: Rescan devices with known IP addresses with every auto-discovery. This option adds devices that already exist in other groups to this group as well and runs the auto-discovery on the newly added devices.
  The auto-discovery does 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 manually.

We recommend that you use the default value.

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

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

Location (for Geo Maps)

If you want to use Geo Maps, enter a location in the first line. Geographical maps then display objects like devices or 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, as PRTG automatically parses latitude and longitude, for example, enter 49.452778 11.077778, or enter 49.452778 any 11.077778 text.

A minus sign (–) in the first line hides 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 then shows the object with the label in the PRTG geo map.

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

Click to interrupt 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 automatically adds a prefix to use the NT LAN Manager (NTLM) protocol. Do not leave this field empty.

User

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

Password

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

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

User

Enter a login name for the access via Secure Shell (SSH) and Web-based Enterprise Management (WBEM). Usually, you use credentials with administrator privileges.

Login

Define the authentication method to use for login:

• Login via Password: Provide a password for login.
• 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. Make sure that the respective public key is provided on the target machine. For details, see section Monitoring via SSH.

Password

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

Private Key

This field is only visible if you enable Login via Private Key above. Paste a private key into the field (OpenSSH format, unencrypted). Usually, you 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 for the private key change to take effect. For details, see section Monitoring via SSH.

For WBEM Use Protocol

This setting is only relevant if you use WBEM sensors.

Define the protocol to use for WBEM:

• HTTP: Use an unencrypted connection for WBEM.
• HTTPS: Use a Secure Sockets Layer (SSL) encrypted connection for WBEM.

For WBEM Use Port

This setting is only relevant if you use WBEM sensors.

Define the port to use for WBEM:

• 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.

WBEM Port

This setting is only visible if you enable Set manually above. Enter the WBEM port number.

SSH Port

Enter the port number to use for SSH connections.

By default, PRTG automatically uses this setting 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:

• 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 select a sudo or su option above. Enter a username to run the specified command as a user other than root. If you leave this field empty, you run the command as root. Make sure that 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 that you want to use to access data with SSH sensors:

We strongly recommend that you keep the default engine. For now, you can still use the legacy mode to ensure compatibility with your target systems.

• 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 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 interrupt the inheritance. See section Inheritance of Settings for more information.

User

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

Password

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

single sign on (SSO) passwords for vSphere do not support special characters. See the sections for VMware sensors for details.

VMware Protocol

Define the protocol used for the connection to VMware and XenServer:

• HTTPS (recommended): Use a Secure Sockets Layer (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:

• 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 interrupt the inheritance. See section Inheritance of Settings for more information.

SNMP Version

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

• 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 SNMP v2c 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 because of 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. Select the authentication type:

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

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 is entirely deactivated.

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

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:

• 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 select 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. If you provide a key, SNMP data packets are encrypted using the encryption algorithm selected above, which provides increased security. The key must match the encryption key of your device. Enter a string or leave the field empty.

If the key does not match the key configured on the target SNMP device, you do not get an error message.

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

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

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

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

Port for Databases

Define which ports PRTG uses for connections to the monitored databases:

• 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 uses 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 uses for database connections. Enter an integer value.

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

Authentication Mode

Select the authentication method for the connection to the Structured Query Language (SQL) database:

• 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 enable SQL server authentication above. Enter the username for the database connection.

Password

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

Timeout (Sec.)

Enter a timeout in seconds for the request. 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 interrupt the inheritance. See section Inheritance of Settings for more information.

Access Key

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

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

User Credentials

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

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

User

This field is only visible if you enable Username/Password above. Enter the username for access to the Message Queue Telemetry Transport (MQTT) broker.

Password

This field is only visible if you enable 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 Transport Layer Security (TLS).

Transport-Level Security

Select 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 enable Use TLS encryption above. Select 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 (CA) certificate for verifying the MQTT server and paste it here.

The certificate must be in Privacy-Enhanced Mail (PEM) format.

Client Authentication

This field is only visible if you enable Use TLS encryption above. Select 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 interrupt 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

This setting is only valid for hybrid sensors offering performance counter and Windows Management Instrumentation (WMI) technology. The setting is ignored for all other sensors.

Define the method Windows sensors use to query data:

• 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, the sensor returns no data.

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

Timeout Method

Specify the time the sensor waits for the return of its WMI query before canceling it with an error message:

• 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: Manually enter a timeout value. We recommend that you use the default value. Only if you experience ongoing timeout errors, try to increase the timeout value.

Timeout Value (Sec.)

This field is only visible if you enable Set manually above. Enter the time the sensor waits for the return of its WMI query before canceling with an error message. Enter an integer value. The maximum value is 900 seconds (15 minutes).

Click to interrupt 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 PRTG waits between two SNMP requests. This can help increase device compatibility. Enter an integer value. We recommend that you use the default value. If you experience SNMP connection failures, increase the delay. You can define a delay between 0 and 100, higher delays are not supported and are discarded.

Failed Requests

Define if an SNMP sensor tries again after a request fails:

• Retry (recommended): Try again if an SNMP request fails. This can help prevent false error messages because of temporary timeout failures.
• Do not retry: Do not retry if an SNMP request fails. If you enable this setting, an SNMP sensor shows a Down status earlier.

Overflow Values

Define how PRTG handles overflow values. Some devices do not correctly handle internal buffer overflows. 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. Select 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 handles 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 searches for on a device:

• Use 64-bit counters if available (recommended): The interface scan uses 64-bit traffic counters, if available. This can avoid buffer overflows in the devices.
• Use 32-bit counters only: The interface scan always uses 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 object identifiers (OID), it automatically polls 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 are 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, several fields with interface descriptions are usually available. They are different for every device and OID. PRTG uses 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 creates 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 get 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 reacts if you change port names in your physical device (for example, a switch or router):

• 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 tries 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 is used for SNMP interface identification:

• Automatic (recommended): Tries the ifAlias field first to identify an SNMP interface and then ifDescr.
  ifName is not 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 restart, and if no ifAlias field is 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 no unique ifAlias is 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 starts 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 stops querying the interface range during sensor creation. Use 0 for automatic mode. We recommend that you use the default value.

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

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

This setting only affects monitoring and it 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 the sensors' settings.

Name

Enter the IP address or Domain Name System (DNS) name of the proxy server. If you leave this field empty, no proxy is used.

Port

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

User

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

Only basic authentication is available. 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. Enter a string or leave the field empty.

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

Scanning Interval

Select a scanning interval (seconds, minutes, or hours). The scanning interval determines the amount of time that 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 the sensor has time to reach and check a device again in case a sensor query fails. Depending on the option that you select, the sensor can try to reach and check a device again several times before the sensor shows a 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 a Warning status. Choose from:

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

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

If you define error limits for a sensor's channels, the sensor immediately shows a Down status. No "wait" option applies.

If a channel uses lookup values, the sensor immediately shows a Down status. No "wait" options apply.

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

Exclude Cluster Nodes

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 are not included in sensor scans. By default, this setting is inherited to all objects underneath.

You 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 settings here. They are active at the same time as the parent objects' settings.

Schedule

Select a schedule from the list. Schedules can be used to monitor for a certain time span (days or hours) every week.

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

Schedules are generally inherited. New schedules are added to existing schedules, so all schedules are active at the same time.

Maintenance Window

Specify if you want to set up a one-time maintenance window. During a maintenance window, the current object and all child objects are not monitored. They are in a Paused status instead. Choose between:

• Not set (monitor continuously): No maintenance window is set and monitoring is always active.
• Set up a one-time maintenance window: Pause monitoring within a maintenance window. You can define a time span for a monitoring pause below and change it even for a currently running maintenance window.

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

Maintenance Begins

This field 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 maintenance window.

Maintenance Ends

This field 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 maintenance window.

Dependency Type

Define a dependency type. You can use dependencies to pause monitoring for an object depending on the status of another 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 another specific sensor is in a Down status or in a Paused status caused by another dependency.

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

To 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 field is only visible if you enable Select a sensor above. Click the Search button and use the object selector to select a sensor on which the current object will depend.

Dependency Delay (Sec.)

This field is only visible if you enable Select a sensor above. Define a time span in seconds for dependency delay.

After the master sensor for this dependency comes back to an Up status, monitoring of the dependent objects is 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. Enter an integer value.

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

User Group Access

Define the user groups that have access to the selected object. 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 but it cannot be accessed.
• 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 its settings. They cannot edit access rights settings.
• Full: Users in this group can see the object, review its monitoring results, edit its 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 interrupt 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 interrupt the inheritance. See section Inheritance of Settings for more information.

Unusual Detection

Define if you want to benefit from unusual detection for sensors:

• 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 show an Unusual status if PRTG detects unusual activity.
• Disabled: Do not activate unusual detection. PRTG ignores unusual values for sensors affected by this setting. These sensors do not show an Unusual status.

You can configure the behavior of unusual detection (or completely disable it) in the system settings.

Similar Sensors Detection

Define if you want to activate Similar Sensors analysis:

• 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 does not consider sensors affected by this setting during similarity analysis.

You can configure the depth of analysis of similar sensors detection (or disable it completely) in the system settings.

System Information

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

• 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 automatically uses the Credentials for Windows Systems and the Credentials for SNMP Devices as defined in the device settings or as inherited from a parent object like the Root group. Consider this when you monitor devices outside the local network, especially when using SNMP v1 or SNMP 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 are 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 Limit number of sensors in this group above. Define how many sensors are allowed in this group and its subgroups. Sensors that exceed this group sensor limit are paused. Enter an integer value.

Sensors in a 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 override the sensor message "exceeds group sensor limit".