To upgrade the current license of your cisco asa firewall, you need to order a new license key from Cisco at www.cisco.com/go/license. You will receive a new license key in your email after a couple of hours. This license key is a five element hexadecimal string in the form 0xffd8624e (as an example).

To apply this new license key in your security appliance, configure the following:

ASA5500(config)#  activation-key 0xffd8624e
ASA5500(config)#exit
ASA5500#copy running startup
ASA5500#reload

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4. Cisco ASA Virtual Firewall Configuration
5. IOS Packet Capture and Auto Upgrade
6. Cisco ASA 5505 Vlans and Licensing
7. Using the Management Interface of the Cisco ASA Firewall