3Com S7902E, Configuration Manual

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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
—
Configure the default MED value default med med-value
Optional
0 by default
Enable the comparison of MED of routes from different ASs
Follow these steps to enable the comparison of MED of routes from different ASs:
To do… Use the command… Remarks
Enter system view
system-view
—
Enter BGP view bgp as-number
—
Enable the comparison of MED of
routes from different ASs
compare-different-as-med
Required
Not enabled by default
Enable the comparison of MED of routes from each AS
Route learning sequence may affect optimal route selection.