【单选题】It’s a configuration that experts are calling a "firewall sandwich," with the second firewall providinga second level of load balancing after traffic down. What is meant by the term "firewall sandwich...
A.
single layer of firewalling
B.
multiple layers of firewalling
C.
firewall connections in either an active or standby state
D.
an architecture in which all traffic between firewalls goes through application-specific servers