运行OSPF协议的路由器每10秒钟向它的各个接口发送 (40) 分组,接收到该分组的路由器就知道了邻居的存在。为避免路由信息被重复发送,需要给路由信息包编号。假设每秒钟传送一次路由信息,为确保路由信息包的编号在1年内不重复使用,则编号的最短长度应为 (41) 位。
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Bluetooth is a universal radio interface in the (71) frequency hand that enables portable electronic devices to connect and communicate wirelessly via short-range, ad hoc networks. Each unit can simultaneously communicate with up to (72) other units per piconet. Moreover, each unit can simultaneously (73) to several piconets. Eliminates the need for wires, cables and connectors for and between cordless or mobile phones, modems, headsets, PDAs, Computers, printers, projectors, local area networks, and so on, and paves the way for new and completely different devices and applications. Technology Characteristics (74) symbol rate exploits maximum available (75) bandwidth。
A. messages
B. certificates
C. applets
D. channel
(66) is used to ensure the confidentiality, integrity and authenticity of the two end points in the private network. (67) , an application-layer protocol, authenticates each peer in an IPsec transaction. IKE negotiates security policy, determining which algorithm may be used to set up the tunnel. It also handles the exchange of session keys used for that one transaction. Networks that use (68) to secure data traffic can automatically authenticate devices by using (69) , which verify the identities of the two users who are sending information back and forth. IPsec can be ideal way to secure data in large networks that require secure connections among many devices. Users deploying IPsec can (70) their network infrastructure without affecting the applications on individual computer. The protocol suite is available as a software-only upgrade to the network infrastructure. This alows security to be implemented without costly changes to each computer. Most important, IPsec allows interoperability among different network devices, PCs and other computing systems.
A. secure
B. relation
C. script
D. strict
关羽是佛教中最著名的汉化伽蓝神。( )P89
A. 对
B. 错
KDC分发密钥时,进行通信的两台主机都需要向KDC申请会话密钥。主机与KDC通信时使用的是 (34) 。
A. 临时密钥
B. 二者共享的永久密钥
C. 公开密钥
D. 会话密钮