Which two key components are related to one firewall per ISP design option for e-commerce? (Choose two.)
A . It is a common approach to single-homing.
B . This approach is commonly used in large sites.
C . Any failure on an edge router results in a loss of session.
D . It has one NAT to two ISP-assigned blocks.
E . It is difficult to set up and administer.
Answer: CD