CISCOCCNA認證考試640-810題庫原題7

based on the display of the command output, what does [120/3] represent? 
a. 120 is the udp port for forwarding traffic and 3 is the number of hops. 
b. 120 is the administrative distance and 3 is the metric for that route. 
c. 120 is the bandwidth of the link and 3 is the routing process number. 
d. 120 is the value of the update timer and 3 is the number of updates received for that route.

answer: b 

explanation: 
to decide which route to use, ios uses a concept called administrative distance. administrative distance is a number that denotes how believable an entire routing protocol is on a single router. the lower the number, the better, or more believable the routing protocol. 
route type administrative distance 
connected 0 
igrp 100 
rip 120