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Configuring ebgp between pe and ce – H3C Technologies H3C SecPath F1000-E User Manual

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The domain ID of an OSPF process is included in the routes generated by the process. When an OSPF

route is injected into BGP, the OSPF domain ID is included in the BGP VPN route and delivered as a BGP

extended community attribute.

NOTE:

After configuring an OSPF instance, you must start OSPF by using the same method for starting a
common OSPF process.

For more information about OSPF, see

OSPF Configuration in the IP Routing Volume.

Configuring EBGP Between PE and CE

1.

On a PE

Follow these steps to configure EBGP between PE and CE on a PE:

To do…

Use the command…

Remarks

Enter system view

system-view

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 peer

peer { group-name | ip-address }
as-number as-number

Required

Inject the routes of the local CEs

import-route protocol
[ process-id ] [ med med-value |
route-policy route-policy-name ]

*

Required
A PE needs to inject the routes of
the local CEs into its VPN routing

table so that 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 | 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 networking

scheme

NOTE:

Normally, BGP detects routing loops by AS number. In the hub and spoke networking 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.

On a CE

Follow these steps to configure EBGP between PE and CE on a CE: