Controlling Route Selection

Weight Attribute
The weight attribute is Cisco proprietary, and is considered before any other attribute.
Weight is local to the router and not propagated to other routers.
Weight is a 16-bit value; higher is preferable. Default is 0 if the route is learned from a peer, or 32,768 if sourced locally.

Router(config-router)# neighbor {<IP address> | <group name>} weight <weight>

Local-Preference Attribute
Local preference is a 32-bit value; higher values are preferred. Default value is 100.
Распространяется только в пределах одной AS ! Не переходит в другие !
Общий стандарт.

Configured as a default:
Router(config-router)# bgp default local-preference <value>

Configured per prefix (via a route-map):
Router(config-router)# neighbor {<IP address> | <group name>} route-map <map name> in

MED Attribute
The multi-exit discriminator is used to influence path selection by external neighbors routing into the AS.
Default MED value is 0; lower is preferred.

Configured as a default:
Router(config-router)# default-metric <value>
MED can also be configured per prefix via route-maps.