11-8
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
default-route imported (IPv6 address family view)
Syntax
default-route imported
undo default-route imported
View
IPv6 address family view
Default Level
2: System level
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.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ipv6-family
[Sysname-bgp-af-ipv6] default-route imported
[Sysname-bgp-af-ipv6] import-route ospfv3 1
display bgp ipv6 group
Syntax
display bgp ipv6 group
[
ipv6-group-name
]