This holds the actual destination MAC address this rule matches against, following the identical dependency pattern as the source-MAC address field -- meaningless unless cienaCesAclRuleMatchDstMacAddr is set true for the same rule. An admin populates this specifically when writing rules that care about where traffic is going rather than where it originated, such as restricting access to a specific piece of critical infrastructure by its hardware address. For example, an admin protecting a network appliance would set this field to that device's specific MAC address and set cienaCesAclRuleMatchDstMacAddr to true to build a rule specifically governing traffic destined for that device.