HP 10500 SERIES Configuration Manual page 22

Step
4. Configure an EBGP peer.
5. Allow the local AS number to
appear in the AS_PATH
attribute of a received route,
and set the maximum number
of times that such case is
allowed to appear.
6. Redistribute remote site routes
advertised by the PE.
7. Configure the filtering of
redistributed routes.
8. Configure a filtering policy to
filter the received routes.
BGP checks routing loops by examining AS numbers. When EBGP is used, the MCE advertises routing
information carrying the local AS number to the site and then receives routing updates from the site. The
routing updates carry the AS number of the MCE, so the MCE discards them to avoid routing loops. To
enable the MCE to receive such routes, configure the MCE to allow routing loops.
Routes redistributed from OSPF to BGP on the MCE have their OSPF attributes removed. To enable BGP
to distinguish routes redistributed from different OSPF domains, you must enable the redistributed routes
to carry the OSPF domain ID by configuring the domain-id command in OSPF view. The domain ID is
added to BGP VPN routes as an extended community attribute.
BGP runs in a BGP VPN instance in the same way as it runs in a normal network. For more information
about BGP, see Layer 3—IP Routing Configuration Guide.
Configure a VPN site:
2.
Step
1. Enter system view.
2. Enter BGP view.
3. Configure the MCE as the
EBGP peer.
4. Redistribute the IGP routes of
the VPN.
Configuring IBGP beween MCE and VPN site
If IBGP is used for exchanging routing information between an MCE and VPN sites, configure a BGP
peer for each VPN instance, and redistribute the IGP routes of each VPN instance on the VPN sites.
Configure the MCE:
1.
Command
peer { group-name | ip-address }
as-number as-number
peer { group-name | ip-address }
allow-as-loop [ number ]
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 ] *
14
Remarks
N/A
Optional.
By default, no route redistribution
is configured.
Optional.
By default, BGP does not filter
redistributed routes.
Optional.
By default, BGP does not filter the
received routes.
Remarks
N/A
N/A
N/A
Optional.
A VPN site must advertise the VPN
network addresses it can reach to
the connected MCE.