Cisco IronPort customers that use local AsyncOS upgrade instead of dynamic upgrades will be unable to perform upgrades at this time. We are currently working on a solution that could be implemented by early next week.
* By default, Cisco IronPort appliances are configured to use “dynamic upgrades”
* Service updates are not interrupted because of this issue
How to verify, if you use "dynamic upgrades"?
Please use CLI command "Updateconfig" and verify that "IronPort AsyncOS upgrades" are fetched from "IronPort Servers".
In the interim, customers with local upgrades can take advantage of dynamic IronPort upgrades.
How to perform AsyncOS upgrades?
Please refer the AsyncOS Configuration guide available on Cisco.com or help section from WebUI of appliance: System Administration > Upgrading AsyncOS