Patent ID: 7948997

Claim:
A BGP route evaluation device for evaluating the reachable period of each BGP route for each destination address space, comprising: message receiving means for receiving a BGP update message; route status detecting means for detecting whether each BGP route is active or inactive on the basis of the received BGP update message, where the BGP route that is announced reachable is detected as active; a management table for managing a cumulative period of active time of each BGP route; update means for updating the corresponding cumulative period of active time of the management table on the basis of a detection result of each BGP route status; and evaluation means for computing the ratio of the cumulative period of active time against a given evaluation period for each BGP route; means for detecting periods of which the evaluation period is excluded for BGP routes that are intentionally withdrawn by operators; and means for registering the evaluation exclusion period in the management table, wherein the evaluation means computes the ratio of cumulative period of active time by excluding the exclusion period from the given evaluation period.