221
Step Command
Remarks
5.
Create the BGP-VPN IPv4
unicast family and enter its
view.
address-family ipv4
[
unicast
]
By default, the BGP-VPN IPv4
unicast family is not created.
6.
Enable IPv4 unicast route
exchange with the
specified peer or peer
group.
peer
{
group-name
|
ip-address
[
mask-length
] }
enable
By default, BGP does not
exchange IPv4 unicast routes
with any peer.
7.
Redistribute the routes of
the local CE.
import-route
protocol
[ {
process-id
|
all-processes
}
[
allow-direct
|
med
med-value
|
route-policy
route-policy-name
] * ]
A PE must redistribute the
routes of the local CE into its
VPN routing table so it can
advertise them to the peer PE.
8.
(Optional.) Allow the local
AS number to appear in the
AS_PATH attribute of a
received route, and set the
maximum number of
repetitions.
peer
{
group-name
|
ip-address
[
mask-length
] }
allow-as-loop
[
number
]
By default, BGP discards
incoming route updates that
contain the local AS number.
BGP detects routing loops by
examining AS numbers. In a
hub-spoke network where
EBGP is running between a PE
and a CE, the routing
information the PE advertises to
a CE carries the AS number of
the PE. Therefore, the route
updates that the PE receives
from the CE also include the AS
number of the PE. This causes
the PE to be unable to receive
the route updates. In this case,
you must configure this
command to allow routing loops.
2.
Configure the CE:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP instance view.
bgp
as-number
[
instance
instance-name
]
N/A
3.
Configure the PE as a BGP
peer.
peer
{
group-name
|
ip-address
[
mask-length
] }
as-number
as-number
By default, no BGP peers exist.
4.
Create the BGP IPv4
unicast family and enter its
view.
address-family ipv4
[
unicast
]
By default, the BGP IPv4
unicast family is not created.
5.
Enable IPv4 unicast route
exchange with the
specified peer or peer
group.
peer
{
group-name
|
ip-address
[
mask-length
] }
enable
By default, BGP does not
exchange IPv4 unicast routes
with any peer.
6.
(Optional.) Configure route
redistribution.
import-route
protocol
[ {
process-id
|
all-processes
}
[
allow-direct
|
med
med-value
|
route-policy
route-policy-name
] * ]
A CE must redistribute its routes
to the PE so the PE can
advertise them to the peer CE.
