3com MSR 20-20 참조 매뉴얼

default local-preference value

IPv6 address family view

value: Default local preference, in the range 0 to 4294967295. The larger the 
value is, the higher the preference is.

Use the default local-preference command to configure the default local 
preference.

Use the undo default local-preference command to restore the default value.

By default, the default local preference is 100.

Use this command to affect IPv6 BGP route selection.

# Two devices A and B in the same AS are connected to another AS. Change the 
local preference of B from default value 100 to 180, making the route passing B 
preferred.

<Sysname> system-view

[Sysname] bgp 100

[Sysname-bgp] ipv6-family

[Sysname-bgp-af-ipv6] default local-preference 180 

default med med-value

IPv6 address family view

med-value: MED value, in the range 0 to 4294967295.

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