单项选择题 As an experienced network administrator, you are aware of the knowledge that it is unnecessary to configure complex overlay network topologies while applying Cisco Wide Area Application Services (WAAS) technology. What is most probably the reason for that?（）

多项选择题 Cisco IOS is the software used on the vast majority of Cisco Systems routers and current Cisco network switches. As a network administrator, you are required to configure MPLS on Cisco IOS. In such a situation, which three of the following steps are necessary to take?（）

单项选择题 What is the default severity level of syslog trap messages?（）