3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring IPv6 BGP Route Attributes 477
Configuring IPv6 BGP
Preference and Default
LOCAL_PREF and
NEXT_HOP Attributes
To do so, use the following commands:
n
■ To make sure an IBGP peer can find the correct next hop, you can configure
routes advertised to the peer to use the local router as the next hop. If BGP
load balancing is configured, the local router specifies itself as the next hop of
outbound routes to a peer/peer group regardless of whether the peer
next-hop-local command is configured.
■ In a "third party next hop" network, that is, the two EBGP peers reside in a
common broadcast subnet, the router does not specify itself as the next hop
for routes to the EBGP peer by default, unless the peer next-hop-local
command is configured.
Configuring the MED
Attribute
To configure the MED attribute, use the following commands:
Configuring the
AS_PATH Attribute
To do so, use the following commands:
To do... Use the command... Remarks
Enter system view system-view -
Enter BGP view bgp as-number Required
Enter IPv6 address family view ipv6-family -
Configure preference values
for IPv6 BGP external, internal,
local routes
preference {
external-preference
internal-preference
local-preference |
route-policy
route-policy-name }
Optional
The default preference values
of external, internal and local
routes are 255, 255, 130
respectively
Configure the default value
for local preference
default local-preference
value
Optional
The value defaults to 100
Advertise routes to a
peer/peer group with the local
router as the next hop
peer { ipv6-group-name |
ipv6-address } next-hop-local
Required
By default, the feature is
available for routes advertised
to the EBGP peer/peer group,
but not available to the IBGP
peer/peer group
To do... Use the command... Remarks
Enter system view system-view -
Enter BGP view bgp as-number Required
Enter IPv6 address family view ipv6-family -
Configure a default MED
value
default med med-value Optional
Defaults to 0
Enable to compare MED
values of routes from different
EBGP peers
compare-different-as-med Optional
Not enabled by default
Prioritize MED values of routes
from each AS
bestroute compare-med Optional
Not configured by default
Prioritize MED values of routes
from confederation peers
bestroute
med-confederation
Optional
Not configured by default