What is the default administrative distance of OSPF?（）……

单项选择题Which address is the IPV6 all-RIP-routers muticast group address that is used by RIPng as the destaion address?（）

A. FF02::A
B. FF05::101
C. FF02::9
D. FF02::6

单项选择题Which statement is true, as relates to classful or classless routing?（）

A. Automatic summarization at classful boundries can cause problems on discontinuous subnets
B. EIGRP and OSPF are classful routing protocols and summarize routes by default
C. RIPv1 and OSPF are classless routing protocols
D. Classful routing protocols send the subnet mask in routing updates

单项选择题Which device might be installed at a branch office to enable and manage an IPsec site-to-site VPN?（）

A. Cisco IOS IPsec/SSL VPN client
B. Cisco VPN Clinet
C. ISDN terminal adapter
D. Cisco Adaptive Security Appliance

单项选择题At which layer of the OSI model is RSTP used to prevent loops?（）

A. data link
B. network
C. physical
D. transport

单项选择题Which IPsec security protocol should be used when confidentiality is required?（）

A. PSK
B. AH
C. MD5
D. ESP