3Com Switch 7750 Series
Command Reference Guide – Routing Protocol Chapter 5 BGP Configuration Commands
5-9
Parameter
value: Default local preference to be configured. The range is 0 to 4294967295. By
default, its value is 100.
Description
Use the default local-preference command to configure the default local preference.
Use the undo default local-preference command to restore the default value.
Configuring different local preferences will affect BGP routing selection.
Example
<3Com> system-view
System View: return to User View with Ctrl+Z.
[3Com] bgp 100
[3Com-bgp] default local-preference 180
5.1.10 default med Syntax
default med med-value
undo default med
View
BGP view/BGP multicast address family view
Parameter
med-value: Specified MED value, in the range of 0 to 4294967295. The default
med-value is “0”.
Description
Use the default med command to configure the default MED value of the system.
Use the undo default med command to restore the default MED value of the system.
The multi-exit discriminator (MED) is an external route metric. Different from the local
preference, the MED is exchanged between autonomous systems. After the MED
enters an autonomous system, it will not be sent out of this autonomous system. The
MED attribute is used to select the optimal route, that is, the route with a smaller MED
value is selected. When a router running the BGP obtains routes with the same
destination address but different next hops through different external peers, the route
selection will be based on the MED value. In the case that all other conditions are the
same, the system first selects the route with the smaller MED value as an external
route of the autonomous system.