Internet Protocol videoconferencing (IP/VC) provides which two business benefits? （）

A . Delivering information about changes in health benefit enrollment to all personnel B . Enabling online collaboration among research personnel C . Enabling an interactive virtual classroom for sales personnel in remote locations D . Delivering a strategic business update from the CEO to all personnel

A . Voice gateway B . Private branch exchange (PBX) C . Advanced audio conferencing software D . IP telephone

A . Call management software B . Media Convergence Servers (MCSs) C . Voice gateways D . IP telephone

A . 正确 B . 错误

A . IGMP snooping and Cisco Group Membership Protocol (CGMP) can be used simultaneously on a switch. B . IGMP snooping a nd Cisco Group Membership Protocol (CGMP) were developed to help Layer 3 switches make intelligent forwarding decisions on their own. C . IGMP snooping examines IGMP join/leave messages so that multicast traffic is forwarded only to hosts that sent an IG MP message toward the router. D . IGMP snooping is an IP multicast constraining mechanism for Layer 2 switches. E . IGMP snooping is enabled with the ip multicast - routing global configuration command.

A . 正确 B . 错误

A . Real-time discussions of patient information among remote medical teams B . Reduced travel time for instructors responsible for different geographic sites C . Improved morale and reduced turnover among employees who receive timely business Updates D . Increased sales and customer satisfaction due to current product information disseminated simultaneously to a global sales force by headquarter

A . IP telephones B . Voice gateways C . Call management software D . Media Convergence Servers (MCSs)

A . There are three IGMP modes: dense mode, sparse mode, and sparse - dense mode B . IGMP is used to register individual hosts with a multicast group C . IGMP version 3 enables a multicast receiving host to specify to the router which sources it should forward traffic from D . IGMP messages a re IP datagrams with a protocol value of 2, destination address of 224.0.0.2, and a TTL value of 1 E . IGMP is a multicast routing protocol that makes packet - forwarding decisions independent of other routing protocols such as EIGRP F . IGMP snooping ru ns on Layer 3 router

A .  Ensure that a stateful firewall allows only HTTP traffic destined for valid web server IP addresses. B .  Ensure that a firewall has SYN flood and DDoS protection applied specifically for valid web servers. C .  Ensure that your firewall enforces HTTP protocol compliance to ensure that only valid flows are allowed inand outof your network. D .  Ensure that HTTP is always authenticated. E .  Ensure that your web server is in a different zone than your backend servers such as SQL and DNS.

A . 0～254 B . 0～255 C . 0～256 D . 0～257

A . 16 B . 24 C . 32 D . 48

A . 接口可能封装了PPP协议 B . 物理链路可能有故障 C . 封装的LMI类型可能与远端不一致 D . 如果接口封装了帧中继协议，此时PVC的状态应该是DOWN

A.配置MD5安全算法可以提供可靠地数据加密 B.配置AES算法可以提供可靠的数据完整性验证 C.部署IPsecVPN网络时，需要考虑IP地址的规划，尽量在分支节点使用可以聚合的IP地址段，来减少IPsec安全关联（Security Authentication，SA）资源的消耗 D.报文验证头协议（Authentication Header，AH）可以提供数据机密性

此题为判断题(对，错)。

A．互联网草案 B．互联网协议 C．互联网通讯协议 D．互联网通讯指引