H3C S7500E Series Command Manual page 607

Command Manual – IPv6 Routing
H3C S7500E Series Ethernet Switches
Description
Use the default med command to specify the default MED value.
Use the undo default med command to restore the default.
By default, the default med-value is 0.
The multi-exit discriminator (MED) is an external metric of a route. Different from local
preference, MED is exchanged between ASs and will stay in the AS once it enters the
AS. The route with a lower MED is preferred. When a router running BGP obtains
several routes with the identical destination and different next-hops from various
external peers, it will select the best route depending 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 the best route for the autonomous system.
Examples
# Devices A and B belong to AS100 and device C belongs to AS200. C is the peer of A
and B. Configure the MED of A as 25 to make C select the path from B.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ipv6-family
[Sysname-bgp-af-ipv6] default med 25
5.1.9 default-route imported
Syntax
default-route imported
undo default-route imported
View
IPv6 address family view
Parameters
None
Description
Use the default-route imported command to enable the redistribution of default route
into the IPv6 BGP routing table.
Use the undo default-route imported command to disable the redistribution.
By default, the redistribution is not enabled.
Examples
# Enable the redistribution of default route from OSPFv3 into IPv6 BGP.
Chapter 5 IPv6 BGP Configuration Commands
5-7