3Com S7906E - Switch, Руководство по настройке

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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:
To do… Use the command… Remarks
Enter system view system-view —
Enter BGP view bgp as-number —
Configure the PE as the peer
peer { group-name |
ip-address } as-number
as-number
Required
Configure the route
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.
z
Exchange of BGP routes for a VPN instance is the same as that of ordinary BGP routes.
z
The configuration task in BGP instance view is the same as that in BGP view. For detailed
information, refer to BGP Configuration and BGP Commands in the IP Routing Volume .
z
For information about BGP peer and peer group configuration, refer to BGP Configuration and
BGP Commands in the IP Routing Volume . This chapter does not differentiate between peer and
peer group.
Configuring Route Advertisement Between PEs
Follow these steps to configure route advertisement between PEs:
To do… Use the command… Remarks
Enter system view system-view —
Enter BGP view bgp as-number Required
Configure the remote PE as the
peer
peer { group-name |
ip-address } as-number
as-number
Required