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Combined Licenses in Failover and Clustering

Prior to Cisco ASA Software version 8.3(1), both units in a failover pair required identical licensed feature sets. Given that most designs used the Active/Standby failover configuration, this led to underutilization of licensed capacities. After the changes in Cisco ASA 8.3(1) software, only the following license requirements remain for the ASA devices that participate in failover or clustering:

  • For failover, Cisco ASA 5505, ASA 5510, and ASA 5512-X appliances must have the Security Plus license installed.
  • For clustering, all participating Cisco ASA 5585-X appliances with SSP-10 and SSP-20 must have either the Base license or the Security Plus license. These have to match because all cluster members must have the 10GE I/O feature in the same state.
  • For clustering, each Cisco ASA 5580 and ASA 5585-X unit must have the Cluster feature enabled independently. Cisco ASA 5500-X appliances require Cisco ASA 9.1(4) software to use this feature, and it is enabled by default on all Cisco ASA 5515-X, ASA 5525-X, ASA 5545-X, and ASA 5555-X models and on the Cisco ASA 5512-X with the Security Plus license.
  • For both failover and clustering, all units must have the same encryption license. The Encryption-3DES-AES license must be in the same state on both failover peers and all cluster members.

After satisfying these basic requirements, the rest of the licensed features and capacities from both failover peers and all active cluster members combine to form a single feature set that all the participating devices use concurrently.

License Aggregation Rules

The system follows these steps to create a combined feature set of a failover pair or a cluster:

  1. Each failover unit or cluster member computes its local feature set by combining the permanent and active time-based activation keys using the rules discussed earlier.
  2. For each feature that can be either enabled or disabled, the combined failover or cluster license inherits the best setting from all of the feature sets of the participating devices. For instance, each unit of a cluster enables the IPS Module license if at least one of the members has it enabled in the local feature set.
  3. For each tiered feature, the licensed capacities of the individual units combine up to the platform limit of each member. This happens even if the particular tiered counts for the same feature do not match between all participating members. Consider a failover pair of Cisco ASA 5525-X appliances where both the primary and secondary units have the active AnyConnect Premium Peers licenses for 500 sessions each. After aggregating these capacities, each device in this failover pair allows up to 750 sessions for this feature. Notice that the combined count of 1000 sessions from the individual licenses exceeds the Total VPN session count of 750 for this platform; this causes the downward adjustment.

After license aggregation, each failover peer or cluster member displays an additional section in the output of the show version and show activation-key commands to reflect the combined active feature set of the device. As shown in Example 3-8, this feature set supersedes the licensed feature set of the local unit as long as it continues to participate in a failover pair or a cluster.

Example 3-8 Aggregated Cisco ASA License Information with Failover or Clustering

Failover cluster licensed features for this platform:

Maximum Physical Interfaces      : Unlimited      perpetual

Maximum VLANs                     : 1024           perpetual

Inside Hosts                      : Unlimited      perpetual

Failover                          : Active/Active  perpetual

Encryption-DES                    : Enabled        perpetual

Encryption-3DES-AES               : Enabled        56 days

Security Contexts                 : 4              perpetual

GTP/GPRS                          : Disabled       perpetual

AnyConnect Premium Peers          : 4              perpetual

AnyConnect Essentials             : Disabled       perpetual

Other VPN Peers                   : 10000          perpetual

Total VPN Peers                   : 10000          perpetual

Shared License                    : Disabled       perpetual

AnyConnect for Mobile             : Disabled       perpetual

AnyConnect for Cisco VPN Phone    : Disabled       perpetual

Advanced Endpoint Assessment      : Disabled       perpetual

UC Phone Proxy Sessions           : 54             56 days

Total UC Proxy Sessions           : 54             56 days

Botnet Traffic Filter             : Disabled       perpetual

Intercompany Media Engine         : Disabled       perpetual

10GE I/O                          : Enabled        perpetual

Cluster                           : Enabled        perpetual

This platform has an ASA5585-SSP-20 VPN Premium license.

If a device loses the connection to its failover peer or a cluster for over 30 days, it falls back to its locally licensed feature set. You can use the clear configure failover or clear configure cluster command to manually remove the aggregated license and force the unit to revert to its locally activated features before the 30-day period expires. This capability is useful when splitting failover or cluster members to configure them as shared VPN licensing peers instead.

Aggregated Time-Based License Countdown

If the combined failover pair or cluster license relies on time-based activation keys to activate any features or aggregate licensed capacities, the countdown rules for these keys depend on the feature type:

  • For any features that can be either enabled or disabled, only one participating unit continues the countdown at any given time. When this license expires, another device starts the countdown of its own time-based key for this feature. This way, the total licensed duration for this feature type combines from all applicable time-based activation keys in a failover pair or a cluster. Consider a failover pair where the primary unit has the Botnet Traffic Filter license for 52 weeks and the secondary unit has the same active license for 28 weeks. Only the primary Cisco ASA will continue the countdown of this license for the first 52 weeks of failover pair operation. After this activation key on the primary unit expires, the secondary unit will begin the countdown for another 28 weeks. As the result, you can benefit from the Botnet Traffic Filter feature in this failover pair without interruption for a combined duration of 80 weeks. If a unit loses communication with its failover peer or cluster for less than 30 days, the combined license still covers this period of independent operation for this device. If the interval of separation exceeds 30 days, the device subtracts the entire period from its local time-based license upon restoration of failover or cluster communication.
  • Any time-based keys for tiered capacity features that contribute to the aggregated failover pair of cluster limits continue the countdown concurrently on their respective Cisco ASA units. Assume a cluster of four Cisco ASA 5580 appliances where each member has a 52-week license for ten virtual contexts in addition to the permanent key with two contexts. The combined license of the cluster allows configuring and using up to 48 virtual contexts for 52 weeks because all time-based tiered capacity licenses count down concurrently on all members. After 52 weeks, the combined cluster license drops down to eight security contexts based on the remaining permanent licenses of each member.
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