A CAS resides in a closed network, and can't reach Broadcom licensing servers.
CAS 3.1.7
Download a CAS license from the support.broadcom.com portal and install it manually to CAS from CLI.
1. Download a CAS license. Please follow up on the next article
https://knowledge.broadcom.com/external/article?articleNumber=145804
2. Install the license from CLI
! Import a license from terminal input (typically by pasting the license content with a right-click). Include the passphrase to decrypt the private key if the license has birth-cert and birth-key in it. Press Ctrl-D after pasting the certificate content.
(config-licensing)# inline license-key [passphrase <value>]
! check the license
(config-licensing)# view