CCNA系列认证
多选题What kind of information does a router running a link-state routing protocol need to create and maintain its topological database?（）ALSAs from other routersBBeacons received on point-to-point linksChello packetsDRouting tables received from neighborsES
题目
LSAs from other routers
Beacons received on point-to-point links
hello packets
Routing tables received from neighbors
SAP packets sent by other routers
TTL packets from exclusive routers
相似问题和答案
第1题：
A. LSAs from other routers
B. Beacons received on point-to-point links
C. hello packets
D. Routing tables received from neighbors
E. SAP packets sent by other routers
F. TTL packets from exclusive routers
第2题：
A. Send periodic updates regardless of topology changes.
B. Send entire routing table to all routers in the routing domain.
C. Use the shortest-path algorithm to the determine best path.
D. Update the routing table based on updates from their neighbors.
E. Maintain the topology of the entire network in its database.
第3题：
A.It stores a subset of information from the routing table.
B.It contains routes learned from all protocols to a destination.
C.It provides a database for routes selected and placed into the routing table.
D.Every routing protocol maintains its own forwarding table.
第4题：
In which two ways does the BGP graceful restart capability preserve prefix information during a restart？（）
- A、The peer router sends an end-of RIB message to the restarting router
- B、The peer router immediately removes the BGP routes that it learned from the restarting router from its BGP routing table
- C、The restarting router does not remove any stale prefixes after the timer for stale entries expires
- D、The router establishes BGP sessions with other routers and relearns the BGP routes from other routers that are also capable of graceful restart. The restarting router waits to receive updates from the neighboring routers. When the neighboring routers send end-of-RIB messages to indicate that they are done sending updates， the restarting router starts sending its own updates
- E、The restarting router removes any stale prefixes after the timer for stale entries expires
正确答案:D,E
第5题：
B.network
C.computer
D.server
第6题：
A. hello packets
B. SAP messages sent by other routers
C. LSAs from other routers
D. beacons received on point-to-point links
E. routing tables received from other link-state routers
F. TTL packets from designated routers
第7题：
B.network
C.broadcast
D.multipath
第8题：
A. The sequence numbers are checked, and if the LSA is val id it is entered into the topology database.
B. The LSA is placed in the topological database and an acknowledgement is sent to the transmitting router.
C. The LSA is dropped and a message is sent to the transmitting router.
D. The LSA is flooded imme diately out of all the OSPF interfaces, except the interface from which the LSA was received.
第9题：
Routers running RIP send their advertisement about cost every（ ）seconds.A router also sends an update message whenever an update from another router causes it to change its routing table.
It is possible to use a range of different metrics or costs for the links in a routing protocol.RIP takes the simplest approach,with all link costs being equal（ ）。Thus it always tries to find the minimum hop route.Valid distances are 1 through（ ）。This also limits RIP to running on fairly small networks.
B.routers
C.switches
D.networks
IP网络中广泛使用的路由协议之一是路由信息协议（RIP）。RIP是基于路由算法的路由协议。网络中的路由协议与理想的图算法存在少量的差异。在互联网中，路由器的目的是将数据包转发给不同的。
运行RIP协议的路由器每秒广播一次路由信息，另外，每当路由器收到其他路由器的更新消息而导致其路由表变化时，就会发送更新消息。
路由协议使用不同的度量或成本来建立连接是可能的。RIP采用了最简单的方法，所有链路的成本都等于。这样，它总是试图寻找跳数最少的路径。有效的距离范围是从1到。这也限制了RIP只能在相当小规模的网络上运行。
第10题：
What two things will a router do when running a distance vector routing protocol? （）
- A、Send periodic updates regardless of topology changes.
- B、Send entire routing table to all routers in the routing domain.
- C、Use the shortest-path algorithm to the determine best path.
- D、Update the routing table based on updates from their neighbors.
- E、Maintain the topology of the entire network in its database.
正确答案:A,D