独家报道————CCIE题库.pdf

1、What is BGP synchronization? A: The rule of synchronization states the following: Before a route learned from an IBGP neighbor is entered into the IP routing table or is advertised to a BGP peer, the route must first be known via IGP. 2、which BGP attributes will influence inbound flow? A: MED、AS-PATH，ORIGIN 3、BGP Administrative distance A：BGP has a distance bgp command that allows you to set different administrative distances for three route types: external,internal, and local. External route 20 Internal route 200 Local route 200 4、Which picture is Traffic Shape, why ? A: Policing typically drops excess traffic. Shaping smooth traffic to a specific rate using a buffer. 5、Unequal cost load-sharing A: Router E will select both B and C as next hop to reach network Z.Unequal cost load sharing happening. The variance command is used to determine which routes are feasible for unequal-cost load sharing. Variance defines a multiplier by which a metric may differ, or vary, from the metric of the lowest-cost route. Any route whose metric exceeds the metric of the lowest-cost route, multiplied by the variance, will not be considered a feasible route. The default variance is one, meaning that the metrics of multiple routes must be equal, to load balance. Variance must be specified in whole numbers. The following three conditions must be met for a route to be included in unequal-cost load sharing:  The maximum-paths limit must not be exceeded as a result of adding the route to a load-sharing group.  The next-hop router must be metrically closer to the destination. That is, its metric for the route must be smaller than the local routers metric