3Com 7757 Configuration Manual page 362

362 C 36: BGP C
HAPTER ONFIGURATION
c
Table 299 Configure BGP route attributes
Operation
Configur Configure the default local
e the MED value
MED
attribute
Permit to compare the MED
values of the routes coming
from the neighbor routers in
different ASs.
Configure the local address as the next
hop address when a BGP router advertises
a route.
Configure the Configure the
AS_Path attribute number of local
AS number
occurrences
allowed
Assign an AS
number for a peer
group
Configure that the
BGP update
packets only carry
the pubic AS
number in the
AS_Path attribute
when a peer sends
BGP update
packets to BGP
peers.
CAUTION:
Using routing policy, you can configure the preference for the routes that
■
match the filtering conditions. As for the unmatched routes, the default
preference is adopted.
If other conditions are the same, the route with the lowest MED value is
■
preferred to be the exterior route of the AS.
After BGP load balance is configured, no matter whether the peer
■
next-hop-local command is executed or not, the local router changes the
next hop IP address to its own IP address before advertising a route to its IBGP
peers/peer group.
Command Description
default med Optional
med-value
By default, the
med-value argument is
0.
compare-different-as- Optional
med
By default, the compare
of MED values of the
routes coming from the
neighbor routers in
different ASs is
disabled.
peer group-name Required
next-hop-local
In some network, to
ensure an IBGP
neighbor locates the
correct next hop, you
can configure the next
hop address of a route
to be the local address
for a BGP router to
advertise route
information to IBGP
peer groups.
peer { group-name | Optional
ip-address }
By default, the number
allow-as-loop
of local AS number
[ number ]
occurrences allowed is
1.
peer group-name Optional
as-number as-number
By default, the local AS
number is not assigned
to a peer group.
peer group-name Optional
public-as-only
By default, a BGP
update packet carries
the private AS number.