问题：

[多选] Which three statements are true about TACACS+？（）

A . It is a Cisco proprietary protocol.
B . It runs on TCP port 59. .
C . Authentication and authorization are done at different stages.
D . TACACS+ encrypts the entire body of the packet， but leaves a standard TACACS+ header.
E . It is an industry standard protocol.
F . TACACS+ encrypts both the entire body of the packet and the TACACS+ header.