2012年思科认证（CCNA）考试练习题精选12
2012年思科认证考试备考的朋友，不用为了查找复习资料而烦恼，小编特为广大考生朋友们搜集了有关2012年思科认证（CCNA）考试练习题，帮助大家复习，祝大家考试顺利。
56. What is poison reverse (什么是破坏逆转.？
A. A change to the default update period timer
B. A routing loop that occurs when using second-hand information to update route tables
C. A router virus
D. A version of split-horizon that sends back a “route unreachable” update to the router that the route was learned from, in order to avoid routing loops
57. What is RIP (什么是R I P .？
A. RIP is an older distance vector Interior Gateway Protocol with a 30-second update timer and . maximum of 15 hops (where “i n f i n i t y” is 16 hops.
B. RIP is a new link-state protocol created by Cisco
C. RIP is a proprietary protocol created by Cisco that has two versions; only version 2 is used currently
D. RIP is a distance vector Interior Gateway Protocol with a 224 maximum network diameter (maximum 224 hops.
58. What is IGRP (什么是I G R P .？
A. IGRP is an older distance vector Interior Gateway Protocol with a 30-second update timer and a maximum of 15 hops (where infinity is 16 hops.
B. IGRP is a new link-state protocol created by Cisco
C. IGRP is a proprietary protocol created by Cisco that has two versions; only version 2 isused currently
D. IGRP is a distance vector and Interior Gateway Protocol with a 224 maximum network diameter (maximum 224 hops.
59. What is the purpose of a flash update in IGRP (IGRP中的瞬时更新的目的是什么.？
A. A flash update is a standard 90-second update
B. After three flash updates, a route is considered unreachable
C. A flash update is sent immediately upon a change in the network topology, in order to speed convergence
D. After seven flash updates, a route is removed from the routing table
60. How can the administrator change how IGRP selects routes (管理员如何修改I G R P选择路由的方法.？
A. The administrator can set update timers
B. The administrator can enable or disable split horizon
C. The administrator can set up load balancing across redundant routes
D. The administrator can adjust the metric weights used for determining the route selection