Which three Layer 2 access designs have all of their uplinks in an active state？（）

A.by tracking the status of objects along the path to the e-commerce module
B.by detecting undesirable conditions along the path to the e-commerce module
C.by using the MED to communicate the site preferences for traffic to multiple ISPs
D.by communicating the available prefixes， routing policies， and preferences of each site to its ISP
E.by moving the SLB to a position where selected traffic to and from the servers does not go through the SLB

A.multiple layers of firewalling
B.a method of operating firewalls from multiple vendors
C.firewall connections in either an active or standby state
D.an architecture in which all traffic between firewalls goes through application-specific servers
E.an architecture in which all traffic between firewalls goes through application-specific gateways

A.NetFlow uses five key fields for the flow
B.NBAR examines data in Layers 3 and 4
C.NetFlow examines data in Layers 3 and 4
D.NBAR examines data in Layers 2 through 4
E.NetFlow examines data in Layers 2 through 4