Actually this link is more up to date for the new models since they were supported in this version: of 9.4 code:http://www.cisco.com/c/en/us/td/docs/security/asa/asa94/configuration/general/asa-general-cli/intro-license.html/index.html#pgfId-2258718S...
Yes, the Security Plus license is needed on the 5506-X to support failover (active/standby). Note security contexts are not supported with the 5506, so active/active failover is also not supported.Clustering is not supported either.http://www.cisco.c...