Configuring ibgp between pe and ce – H3C Technologies H3C SR8800 User Manual

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Step Command

Remarks

6.

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.

7.

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.

8.

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.

Configurations on a CE

To configure EBGP between PE and CE:

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter BGP view.

bgp as-number N/A

3.

Configure the PE as the EBGP

peer.

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

N/A

4.

Configure the route

redistribution and
advertisement behavior.

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

route-policy-name ] *

Optional.
A CE needs to advertise its routes
to the connected PE so that the PE

can advertise them to the peer CE.

NOTE:

Exchange of BGP routes for a VPN instance is the same as that of ordinary BGP routes.

The BGP configuration task in BGP-VPN instance view is the same as that in BGP view. For more
information, see

Layer 3—IP Routing Configuration Guide.

For information about BGP peer and peer group configuration, see

Layer 3—IP Routing Configuration

Guide. This chapter does not differentiate between peer and peer group.

Configuring IBGP between PE and CE

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