天津联通DNS系统采用基于anycast技术的分布式DNS架构，实现基于软件的负载均衡功能。

下面关于IPv6任意播（AnyCast）地址的说明中，错误的是（）。

A:这种地址表示一组接口的标识符 B:这种地址只能作为目标地址 C:任意播地址可以指定给IPv6主机 D:任意播地址可以指定给IPv6路由器

We have already covered the topic of network addresses. The first  (1) in a block (in classes A, B, and C) defines the network address. In classes A, B, and C,if the hostid is all ls,the address is called a direct broadcast address. It is used by a(2) to send a packet to all hosts in a specific network. All hosts will accept a packet having this type of destination address. Note that this address can be used only as a (3) address in an IP packet. Note also that this special address also reduces the number of available hostid for each netid in classes A,B，and C． In classes A, B, and C, an address with all ls for the netid and hostid (32bits) define a (4) address in the current network.A host that wants to send a message to every other host can use this address as a destination address in an IP packet. However, a router will block a packet having this type of address to confine the broadcasting to the (5) network. Note that this address belongs to class E.

空白（4）处应选择（）

A:unicast B:multicast C:broadcast D:anycast

Traditional network layer packet forwarding relies on the information provided by network layer （） protocols, or static routing, to make an independent （） decisions at each hop within the network. The forwarding（）is based solely on the destination （） IP address. All packets for the same destination follow the same path across the network if no other equal-cost paths exist. Whenever a router has two equal-cost （） toward a destination, the packets toward the destination might take one or both of them, resulting in some degree of load sharing.

The forwarding decision is based solely on the destination （） IP address.

A:anycast B:multicast C:broadcast D:unicast

下面关于IPv6任意播（AnyCast）地址的说明中，错误的（）。

A:这种地址表示一组接口的标识符 B:这种地址只能作为目标地址 C:任意播地址可以指定给IPv6主机 D:任意播地址可以指定给IPv6路由器

A multicast router may receive thousands of multicast（）every day for different groups. If a router has no knowledge about the membership status of the（）, it must broadcast all of these packets. This creates a lot of traffic and consumes（）. A better solution is to keep a list of groups in the network for which there is at least one loyal member.（）helps the multicast router create and update this list. For each group, there is one router that has the duty of distributing the（）packets destined for that group. This means that if there are three multicast routers connected to a network, their lists of groupids are mutually exclusive. A host or multicast router can have membership in a group.

For each group, there is one router that has the duty of distributing the（）packets destined for that group.

A:anycast B:multicast C:unicast D:broadcast

The API changes should provide both source and binary (71)for programs written to the original API. That is, existing program binaries should continue to operate when run on a system supporting the new API, In addition, existing (72) that are re-compiled and run on a system supporting the new API should continue to operate. Simply put, the API(73) for multicast receivers that specify source filters should not break existing programs, The changes to the API should be as small as possible in order to simplify the task of converting existing (74)receiver applications to use source filters. Applications should be able to detect when the new(75)filter APls are unavailable(e.g., calls fail with the ENOTSUPP error) and react gracefully(e.g., revert to old non-source-filter API or display a meaningful error message to the user).

空白处（74）应选择（）

A:multicast B:unicast C:broadcast D:anycast

Traditional network layer packet forwarding relies on the information provided by network layer  (1) protocols, or static routing, to make an independent (2) decision at each hop within the network. The forwarding  (3) is based solely on the destination  (4) IP address. All packets for the same destination follow the same path across the network if no other equal-cost paths exist. Whenever a router has two equal-cost  (5) toward a destination, the packets toward the destination might take one or both of them, resulting in

空白（4）处应选择（）

A:anycast B:multicast C:broadcast D:unicast

下面关于IPv6任意播（AnyCast）地址的说明中，错误的（）。

A:这种地址表示一组接口的标识符 B:这种地址只能作为目标地址 C:任意播地址可以指定给IPv6主机 D:任意播地址可以指定给IPv6路由器