单项选择题
A.Segment security zones
B.Restrict access to firewalls
C.Use logs and alerts
D.Set connection limits
单项选择题 Whichoneisthemostimportantbasedonthefollowingcommonelementsofanetworkdesign？（）
单项选择题 WhichPublicKeyCryptographicStandards（PKCS）definesthesyntaxforencryptedmessagesandmessageswithdigitalsignatures？（）
单项选择题 Examinethefollowingoptions，whichSpanningTreeProtocol（STP）protectionmechanismdisablesaswitchportiftheportreceivesaBridgeProtocolDataUnit（BPDU）？（）