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Configuring eBGP between PE and CE
1.
Configure the PE
To configure the PE:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enable BGP and enter BGP view
bgp
as-number
—
Enter BGP VPN instance view
ipv4-family vpn-instance
vpn-instance-name
Required
Configure the CE as the VPN eBGP
peer
peer
{
group-name
|
ip-address
}
as-number
as-number
Required
Redistribute the routes of the local
CEs
import-route
protocol
[
process-id
]
[
med
med-value
|
route-policy
route-policy-name
] *
Required
A PE must redistribute the routes of
the local CEs into its VPN routing
table so it can advertise them to the
peer PE.
Configure BGP to filter routes to be
advertised
filter-policy
{
acl-number
|
ip-prefix
ip-prefix-name
}
export
[
direct
|
isis
process-id
|
ospf
process-id
|
rip
process-id
|
static
]
Optional
By default, BGP does not filter
routes to be advertised.
Configure BGP to filter received
routes
filter-policy
{
acl-number
|
ip-prefix
ip-prefix-name
}
import
Optional
By default, BGP does not filter
received routes.
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
}
allow-as-loop
[
number
]
Optional
For the hub and spoke network
scheme
NOTE:
Normally, BGP detects routing loops by AS number. In the hub and spoke network scheme, however, with
eBGP running between PE and CE, the routing information the PE advertises to a CE carries the number of
the AS where the PE resides. Therefore, the route updates that the PE receives from the CE also include the
number of the AS where the PE resides. This causes the PE unable to receive the route updates. In this case,
routing loops must be allowed.
2.
Configure the CE
To configure the CE:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp
as-number
—
Configure the PE as the eBGP peer
peer
{
group-name
|
ip-address
}
as-number
as-number
Required
Configure the route redistribution
and advertisement behavior
import-route
protocol
[
process-id
]
[
med
med-value
|
route-policy
route-policy-name
] *
Optional
A CE must advertise its routes to the
connected PE so the PE can
advertise them to the peer CE.
