H3C SR8800 10G Mpls Configuration Manual page 281

Step
6. Redistribute remote site routes
advertised by the PE.
Configure a filtering policy to
7.
filter the routes to be
advertised.
8. Configure a filtering policy to
filter received routes.
NOTE:
Normally, BGP checks routing loops by examining AS numbers. If EBGP is used between the MCE and
•
a site, when the MCE advertises its routing information with its AS number to the site and then receives
routing update information from the site, the route update message will carry the AS number of the
MCE, making the MCE unable to receive this route update message. In this case, to enable the MCE to
receive route updates normally, configure the MCE to allow routing loops.
• In standard BGP/OSPF route redistribution, when a route is redistributed into OSPF from BGP on the
MCE, the route's original OSPF attribute cannot be restored, making the route unable to be
distinguished from routes redistributed from other domains. To distinguish routes of different OSPF
domains, you need to enable a route to carry the OSPF domain ID when the route is redistributed from
OSPF into BGP on the peer PE. Thus, the domain ID of an OSPF process is carried in a route generated
by the process. When the OSPF route is redistributed into BGP, the domain ID is added to the BGP VPN
route and is transmitted over the network as the extended community attribute of BGP.
After you configure a BGP VPN instance, the BGP route exchange in the VPN instance is the same as the
•
common BGP's. For more information about BGP configuration, see
Guide
.
Configurations on a VPN site
2.
To configure the VPN site:
Step
1. Enter system view.
2. Enter BGP view.
3. Configure the MCE as the
EBGP peer.
Redistribute the IGP routes of
4.
the VPN.
Configuring IBGP beween MCE and VPN site
If IBGP is used for exchanging routing information between an MCE and VPN sites, you must configure
a BGP peer for each VPN instance respectively, and redistribute the IGP routes of each VPN instance on
the VPN sites.
Command
import-route protocol [ process-id
| all-processes ] [ med med-value |
route-policy route-policy-name ] *
filter-policy { acl-number |
ip-prefix ip-prefix-name } export
[ direct | isis process-id | ospf
process-id | rip process-id | static ]
filter-policy { acl-number |
ip-prefix ip-prefix-name } import
Command
system-view
bgp as-number
peer { group-name | ip-address }
as-number as-number
import-route protocol [ process-id ]
[ med med-value | route-policy
route-policy-name ] *
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Remarks
By default, no routes of any other
protocol are redistributed to BGP.
Optional.
By default, BGP does not filter the
routes to be advertised.
Optional.
By default, BGP does not filter the
received routes.
Layer 3—IP Routing Configuration
Remarks
N/A
N/A
N/A
Optional.
A VPN site must advertise the VPN
network addresses it can reach to
the connected MCE.