单项选择题
A.A request made by a node for the IP address of the local router
B.A request made by a node to join a specified multicast group
C.A request made by a node for a DHCP provided IP address
D.A request made by a node for the IP address of the DHCP server
单项选择题 InwhichwaycantheIPv6addressof2031：0000：130F：0000：0000：09C0：876A：130Bbeexpressedmostefficiently？（）
单项选择题 Twodirectlyconnectedrouters，R1andR2，arebothconfiguredforOSPFgracefulrestart.R2isabletoswitchpacketsinhardware，butR1isnot.IfanetworkadministratorlogsontoR2andperformsasystemreload，whichwillbetheresult？（）
单项选择题 Asanetworkadministrator，canyoutellmewhattherootguardfeatureprovidesinabridgednetwork？（）