PaloAlto Virtual Systems Test

Virtual systems are multiple, logical firewall instances within a single Palo Alto Networks physical firewall. Each virtual system is an independent, separately managed logical firewall with its traffic kept separate from that of others. A typical scenario where virtual systems are used is a deployment scenario i.e., two physical firewalls (a HA pair) can be configured as virtual systems for use by tenants of a Managed Security Service Provider. In such environments, administrators can exists in different levels of the system. With the help of virtual systems, administrators can control access to the device level as well as specific management functions (enable, disable, hide) for each firewall customer or user. The flexibility and efficiencies of virtual systems present managed service providers (MSP) and enterprises with some very attractive possibilities to enhance business efficiencies such as improved scalability, low capital expenditure and reduced operational cost.

For efficiently monitoring the traffic through the physical firewall, each administrator of the environment can be assigned with a limited number of virtual systems. If the super administrator of the environment wants to figure out how well sessions are utilized in a virtual server, then he/she can monitor the individual virtual systems and figure out the session load on each virtual system. By continuously monitoring the virtual systems, the super administrator can easily identify the virtual system that is overloaded and further investigate the real reason behind such overload. The PaloAlto Virtual Systems test helps administrators to continuously monitor the session load on the virtual systems.

For each virtual system configured on the Palo Alto Firewall, this test reports the number of active sessions that are active on the virtual system and the percentage of sessions utilized. This test provides administrators effective pointers on the current session load on the virtual systems and identify overloaded virtual systems, if any.

Target of the test : A Palo Alto Firewall

Agent deploying the test : An external agent

Outputs of the test : One set of results for each virtual system configured on the target firewall being monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.


The IP address of the host for which this test is to be configured.


Enter the port number at which the specified host listens to. By default, this is Null.


The port at which the monitored target exposes its SNMP MIB; The default value is 161.


By default, the eG agent supports SNMP version 1. Accordingly, the default selection in the SNMPVersion list is v1. However, if a different SNMP framework is in use in your environment, say SNMP v2 or v3, then select the corresponding option from this list.


The SNMP community name that the test uses to communicate with the firewall. This parameter is specific to SNMP v1 and v2 only. Therefore, if the SNMPVersion chosen is v3, then this parameter will not appear.


This parameter appears only when v3 is selected as the SNMPVersion. SNMP version 3 (SNMPv3) is an extensible SNMP Framework which supplements the SNMPv2 Framework, by additionally supporting message security, access control, and remote SNMP configuration capabilities. To extract performance statistics from the MIB using the highly secure SNMP v3 protocol, the eG agent has to be configured with the required access privileges – in other words, the eG agent should connect to the MIB using the credentials of a user with access permissions to be MIB. Therefore, specify the name of such a user against this parameter. 


This parameter appears only when v3 is selected as the SNMPVersion. An SNMP context is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context and an SNMP entity potentially has access to many contexts. A context is identified by the SNMPEngineID value of the entity hosting the management information (also called a contextEngineID) and a context name that identifies the specific context (also called a contextName). If the Username provided is associated with a context name, then the eG agent will be able to poll the MIB and collect metrics only if it is configured with the context name as well. In such cases therefore, specify the context name of the Username in the Context text box.  By default, this parameter is set to none.


Specify the password that corresponds to the above-mentioned Username. This parameter once again appears only if the SNMPVersion selected is v3.

Confirm Password

Confirm the AuthPass by retyping it here.


This parameter too appears only if v3 is selected as the SNMPversion. From the Authtype list box, choose the authentication algorithm using which SNMP v3 converts the specified username and password into a 32-bit format to ensure security of SNMP transactions. You can choose between the following options:

  • MD5 – Message Digest Algorithm
  • SHA – Secure Hash Algorithm


This flag appears only when v3 is selected as the SNMPversion. By default, the eG agent does not encrypt SNMP requests. Accordingly, the this flag is set to No by default. To ensure that SNMP requests sent by the eG agent are encrypted, select the Yes option. 


If this EncryptFlag is set to Yes, then you will have to mention the encryption type by selecting an option from the EncryptType list. SNMP v3 supports the following encryption types:

  • DES – Data Encryption Standard
  • AES – Advanced Encryption Standard


Specify the encryption password here.

Confirm Password

Confirm the encryption password by retyping it here.


Specify the duration (in seconds) within which the SNMP query executed by this test should time out in this text box. The default is 10 seconds.

Data Over TCP

By default, in an IT environment, all data transmission occurs over UDP. Some environments however, may be specifically configured to offload a fraction of the data traffic – for instance, certain types of data traffic or traffic pertaining to specific components – to other protocols like TCP, so as to prevent UDP overloads. In such environments, you can instruct the eG agent to conduct the SNMP data traffic related to the monitored target over TCP (and not UDP). For this, set this flag to Yes. By default, this flag is set to No.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Active sessions

Indicates the number of sessions that are active on this virtual system.


This measure is a good indicator of the session load on the virtual system.

Compare the value of this measure across virtual systems to identify the virtual system that is constantly overloaded.

Session utilization

Indicates the percentage of utilization of session on this virtual system.


A high value for this measure is an indication of overload condition on the virtual system.