多项选择题
A. only the low-order 23 bits of the MAC address are used to map IP addresses
B. only the low-order 24 bits of the MAC address are used to map IP addresses
C. only the high-order 23 bits of the MAC address are used to map IP addresses
D. only the low-order 23 bits of the IP address are used to map MAC addresses
E. the 0x01004f MAC address prefix is used for mapping IP addresses to MAC addresses
F. the 0x01005e MAC address prefix is used for mapping IP addresses to MAC addresses
单项选择题 Which routing protocol supports a flexible area structure using routing levels one and two?（）
单项选择题 Which site-to-site VPN solution allows Cisco routers, PIX Firewalls, and Cisco hardware clients to act as remote VPN clients in order to receive predefined security policies and configuration parameters from the VPN headend at the central site?（）
单项选择题 When designing the WAN module within the enterprise edge, which document is used to specify the connectivity and performance agreements with the service provider?（）