单项选择题
Cat6500（config）# router ospf 1 Cat6500（config-router）# network 0.0.0.0 255.255.255.255 area 0 Cat6500（config-router）# nsf Cat6500（config-router）#end Refer to the exhibit. The configuration is used to enable nonstop forwarding for OSPF on a Catalyst 6500 Series Switch with redundant supervisor engines. The default CEF configuration is unchanged. After testing， user traffic is interrupted and NSF is not operational. What is the most likely reason？ （）
A.CEF was not properly configured. B.OSPF was not properly configured for graceful restart. C.Stateful switchover was not correctly configured. D.NSF for OSPF is only supported in area 0.
单项选择题 To initiate testing， which port does a Cisco IOS IP SLA source use to send a control message to an IP SLA responder？ （）
多项选择题 WhichtwoitemsbestdescribeaCiscoIOSIPSLAresponder？（）
多项选择题 WhichtwostatementsbestdescribeCiscoIOSIPSLA？（）
