Configuring preferences for bgp routes, Configure the default local preference, Configuring the med attribute – H3C Technologies H3C S10500 Series Switches User Manual
Page 229: Configure the default med value
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Configuring preferences for BGP routes
A router can run multiple routing protocols with each having a preference. If they find the same route, the
route found by the routing protocol with the highest preference is selected.
This task allows you to configure preferences for external, internal, and local BGP routes, and reference
a routing policy to set preferences for matching routes as needed.
Follow these steps to configure preferences for BGP routes:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—
Configure preferences for external, internal,
and local BGP routes
preference { external-preference
internal-preference
local-preference | route-policy
route-policy-name }
Optional
The default preferences of
external, internal, and local
BGP routes are 255, 255,
and 130, respectively.
Configure the default local preference
The local preference is used to determine the best route for traffic leaving the local AS. When a BGP
router obtains from several iBGP peers multiple routes to the same destination but with different next hops,
it considers the route with the highest local preference as the best route.
This task allows you to specify the default local preference for routes sent to iBGP peers.
Follow these steps to specify the default local preference:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—
Configure the default local preference
default local-preference value
Optional
100 by default
Configuring the MED attribute
MED is used to determine the best route for traffic going into an AS. When a BGP router obtains from
eBGP peers multiple routes to the same destination but with different next hops, it considers the route with
the smallest MED value as the best route if other conditions are the same.
Configure the default MED value
Follow these steps to configure the default MED value:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—