Cisco ASA Series Cli Configuration Manual page 191

Chapter 1 Managing Feature Licenses
that time, then the backup server will only have a 10-day limit left over. The backup server "recharges"
up to the maximum 30 days after 20 more days as an inactive backup. This recharging function is
implemented to discourage misuse of the shared license.
Failover and Shared Licenses
This section describes how shared licenses interact with failover and includes the following topics:
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Failover and Shared License Servers
This section describes how the main server and backup server interact with failover. Because the shared
licensing server is also performing normal duties as the ASA, including performing functions such as
being a VPN gateway and firewall, then you might need to configure failover for the main and backup
shared licensing servers for increased reliability.
Note
The backup server mechanism is separate from, but compatible with, failover.
Shared licenses are supported only in single context mode, so Active/Active failover is not supported.
For Active/Standby failover, the primary unit acts as the main shared licensing server, and the standby
unit acts as the main shared licensing server after failover. The standby unit does not act as the backup
shared licensing server. Instead, you can have a second pair of units acting as the backup server, if
desired.
For example, you have a network with 2 failover pairs. Pair #1 includes the main licensing server. Pair
#2 includes the backup server. When the primary unit from Pair #1 goes down, the standby unit
immediately becomes the new main licensing server. The backup server from Pair #2 never gets used.
Only if both units in Pair #1 go down does the backup server in Pair #2 come into use as the shared
licensing server. If Pair #1 remains down, and the primary unit in Pair #2 goes down, then the standby
unit in Pair #2 comes into use as the shared licensing server.
The standby backup server shares the same operating limits as the primary backup server; if the standby
unit becomes active, it continues counting down where the primary unit left off. See the
About the Shared Licensing Backup Server" section on page 1-28
Failover and Shared License Participants
For participant pairs, both units register with the shared licensing server using separate participant IDs.
The active unit syncs its participant ID with the standby unit. The standby unit uses this ID to generate
a transfer request when it switches to the active role. This transfer request is used to move the shared
sessions from the previously active unit to the new active unit.
Maximum Number of Participants
The ASA does not limit the number of participants for the shared license; however, a very large shared
network could potentially affect the performance on the licensing server. In this case, you can increase
the delay between participant refreshes, or you can create two shared networks.
"Failover and Shared License Servers" section on page 1-29
"Failover and Shared License Participants" section on page 1-29
Information About Feature Licenses
for more information.
Cisco ASA Series CLI Configuration Guide
"Information
1-29