Question

How to manage the maximum borrow duration for Flexnet based licensing.

Answer

For FNP licensing, both, certificate based licensing and trusted storage based licensing based borrow checkout (/activation) can be managed for a maximum specified duration.

For Certificate Based Licensing:

For certificate based licensing, the options file keyword "MAX_BORROW_HOURS" provides the option to limit the duration for which a license can be borrowed.

General Method to borrow the licenses: By adding the BORROW[n]keyword in the INCREMENT/FEATURE line. The value, n, is the maximum number of hours for which the license can be borrowed. The default value is 168 (hours), which equates to one week. The maximum borrow period is platform
dependent. Typically, a value under 60000 hours works on most platforms.

MAX_BORROW_HOURS

This option is used for licenses held in license files. When licenses are available in trusted storage, normally 
activation is provided instead of BORROW.

Syntax:    MAX_BORROW_HOURS feature[:keyword=value] num_hours

This options file entry changes the maximum period a license can be borrowed from that specified in the license file for feature. The new period
must be less than that in the license file.

NOTE: If multiple MAX_BORROW_HOURS keywords appear in the options file, only the last one is applied to feature

For Trusted Based Licensing:

For TS based licensing, there isn't an exact concept of borrow, but its known as "Activation".

Using the BORROW keyword, a maximum borrow period is defined. To limit the possible misuse of borrowed licenses, the default borrow period is set to one week. Licenses obtained using the activation borrow capability are secure: starting and stopping the license server does not allow for extra uses. There is no provision for defining a maximum borrow period with the activation borrow capability. Licenses borrowed using the activation borrow capability cannot have an expiration date later than the expiration date of the source fulfillment record on the license server.

Starting FNP-11.12.1 (Released in 2014), a new options file keyword was introduced with an option to specify the maximum duration for which a TS license can be activated on the clients i.e. "ACTIVATION_EXPIRY_DAYS "

Quoting the FNP-11.12.1 release note:

ACTIVATION_EXPIRY_DAYS

This option controls the activation request based on the expiration date mentioned in the options file during activation
Publisher controls the activation based on the number of expiration days.

Syntax: 
- ACTIVATION_EXPIRY_DAYS entitlement ID days
- ACTIVATION_EXPIRY_DAYS entitlementID:FID=fulfillmentID days

Example:

ACTIVATION_EXPIRY_DAYS ENTL-EZCALC 3

As per the example, if the current date is 29-December-XXXX then the client can activate the license until 31-dec-XXXX. In case of normal activation without the options file, the client can use the license beyond 31-dec-XXXX

NOTE: If more than one ACTIVATION_EXPIRY_DAYS option for the same entitlement ID and fulfillment ID with different count of days is specified in the options file, then the functionality always considers the first line and ignores subsequent lines.

NOTE: The BORROW and activation borrow capabilities are not compatible with use of three server redundant configuration. This is because persistent data is held on a single license server: for the BORROW capability, this is the borrow data-cache and for the activation borrow capability this is the data required to add the license back in to the concurrent license pool when the borrowed license expires. Note that it is a general limitation of activation that it is not supported on a three redundant server configuration.