MACsec Intel® FPGA IP User Guide

ID 736108
Date 10/21/2022
Public

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4.6. MACsec Software Rekeying

When PN is about to expire, rekeying occurs. An example of a sequence that can happen is shown below.

Transmit SA:

  1. Set “Enable Transmission enable” to False (the default value is False) for new SA.
  2. Choose a security association and program the following configuration:
    1. Set the Key value for the SA.
    2. Set the next packet number value for the SA.
    3. Set the confidentiality offset value for the SA.
    4. Initialize all the stats configuration.
  3. Ensure no Tx traffic entering the MACsec IP is using the expired SA.
    1. Set “Enable Transmission enable” to False for expired SA.
    2. Set “Enable Transmission enable” to True for new SA.

Receive SA:

  1. Set “Enable Receive enable” to False (the default value is False) for new SA.
  2. Choose a security association and program the following configuration:
    1. Set the Key value for the SA belonging to the SC.
    2. Set the next packet number value for the SA belonging to the SC.
    3. Set the lowest PN value for the SA belonging to the SC.
    4. Initialize all the stats configuration.
  3. Set “Enable Receive enable” to True (the default value is False) for new SA.
  4. Ensure the Rx traffic entering the MACsec IP is using the new SA.
  5. Set “Enable Receive enable” to False (the default value is False) for the expired SA.