H3C Technologies H3C S10500 Series Switches - Manual (Page 261)

250
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. Configurations on a CE
Follow these steps 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.
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
NOTE:
iBGP can be used between PE and CE devices in only common MPLS L3VPN network. In networks such as
Extranet, inter-AS VPN, carrier’s carrier, nested VPN, and HoVPN, you cannot use iBGP between PE and
CE devices.
1. Configurations on a PE
Follow these steps to configure iBGP between PE and CE:
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 iBGP
peer peer { group-name | ip-address }
as-number as-number
Required