Which of the following statements are true about IPsec VPNs? (Choose three.)
A.
IPsec increases overhead and bandwidth.
B.
IPsec operates at the layer 2 of the OSI model.
C.
End-user’s network applications must be properly pre-configured to send traffic across the IPsec VPN.
D.
IPsec protects upper layer protocols.
E.
IPsec operates at the layer 3 of the OSI model.