BGP的导入导出策略

 

如果从导入和导出两个方面对BGP策略进行划分的话，那么

导入方面：

(1) After receiving a route announcement, a BGP router dis-

cards the route if its own AS number is present in the AS

path to avoid a loop in AS path.

(2) The router then applies

import policies to this route which include denying, or per-

mitting a route,

(3) and assigning a local preference to indicate

how favorable the route is.

导出方面：

(1) permitting

or denying a route

(2) assigning MED to control the inbound

tra_c

(3) tagging a BGP community to indicate what prefer-

ence a neighboring AS should assign to it

(4) prepending

AS paths or redistributing its pre_xes to a_ect the inbound

traffic