BGP Attributes

Routes learned via BGP have associated properties that are used to determine the best route to a destination when multiple paths exist. These properties are called BGP attributes. An under-standing of how BGP attributes influence route selection is required for the design of robust networks. This section describes the attributes that BGP uses in the route selection process:

  • Weight

  • Local preference

  • Multi-exit discriminator

  • Origin

  • AS_path

  • Next-hop

  • Community

Weight Attribute

Weight is a Cisco-defined attribute that is local to a router. The weight attribute is not advertised to neighboring routers. If the router learns about more than one route to the same destination, the route with the highest weight is preferred. In Figure A-2, Router ...

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