VPN Tunnels Test

A VPN (Virtual Private Network) creates secure connections between computers or networks in different locations. Each connection is known as a tunnel. When a VPN tunnel is created, the two tunnel endpoints authenticate with each other. Data in the tunnel is encrypted. Only the sender and the recipient of the traffic can read it.

Using the FortiGate Firewall, administrators can configure multiple VPN tunnels based on the volume of data traffic handled by their network and the security/privacy requirements of the network. Often bandwidth management can be enabled on the firewall configurations to prevent unauthorized access to the network and to optimize the usage of network resources. Improper firewall configurations can therefore result in a few VPN tunnels hogging the bandwidth resources and choking the network! To avoid this, administrators should periodically check the efficacy of the firewall configuration, identify the issues in the firewall settings and rectify the same! This is where the VPN Tunnels test helps!

This test auto discovers the VPN tunnels configured using the FortiGate Firewall and reports the status of each tunnel. This test also closely monitors the amount of data traffic sent and received via every tunnel. In the process, the test accurately points to that tunnel that is handling an abnormally high volume of traffic and is hence hogging the bandwidth resources available to the network! This way, the test enables administrators to understand whether/not their firewall configurations are effective, and if not, initiate measures to fine-tune them.

Target of the test : A FortiGate Firewall

Agent deploying the test : An external agent

Outputs of the test : One set of results for each VPN tunnel created on the target firewall being monitored

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

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

Port

Refers to the port at which the specified host listens to.

SNMPPort

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

SNMPVersion

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.

SNMPCommunity

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.

UserName

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. 

Context

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.

AuthPass

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.

AuthType

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
  • SHA224 - Secure Hash Algorithm 224 bit
  • SHA256 - Secure Hash Algorithm 256 bit
  • SHA384 - Secure Hash Algorithm 384 bit
  • SHA512 - Secure Hash Algorithm 512 bit

EncryptFlag

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. 

EncryptType

If the 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
  • 3DES - Triple Data Encryption Standard
  • AES - Advanced Encryption Standard
  • AES128 - Advanced Encryption Standard 128 bit
  • AES192 - Advanced Encryption Standard 192 bit
  • AES256 - Advanced Encryption Standard 256 bit

EncryptPassword

Specify the encryption password here.

Confirm Password

Confirm the encryption password by retyping it here.

Timeout

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.

EngineID

This parameter appears only when v3 is selected as the SNMPVersion. Sometimes, the test may not report metrics when AES192 or AES256 is chosen as the Encryption type. To ensure that the test report metrics consistently, administrators need to set this flag to Yes. By default, this parameter is set to No.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

VPN tunnel status

Indicates the current state of this VPN tunnel.

 

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure value

Numeric Value

Up

 2

Down

 1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current state of this VPN tunnel. The graph of this measure however is represented using the numeric equivalents only - 0 or 1.

Data transmitted

Indicates the amount of data transmitted through this VPN tunnel.

KB

Comparing the value of this measure across tunnels helps you to identify the tunnel that is transmitting the maximum amount of data.

Data received

Indicates the amount of data received through this VPN tunnel.

KB

Comparing the value of this measure across tunnels helps you to identify the tunnel that is receiving the maximum amount of data.

VPN tunnels health

Indicates the health of this VPN tunnel, expressed in percent.

Percentage

A sudden/gradual decrease in the value of this measure indicates that the VPN tunnel is encountering frequent connectivity issues.