HP HSR6800 Configuration Manual page 293

Step
5. Allow the local AS number
to appear in the AS_PATH
attribute of a received route
and set the maximum
number of repetitions.
6. Redistribute remote site
routes advertised by the
PE.
7. Configure a filtering policy
to filter the routes to be
advertised.
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.
2. Configure the VPN site:
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 between 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, and redistribute the IGP routes of each VPN instance
on the VPN sites.
1. Configure the MCE:
Step
1. Enter system view.
2. Enter BGP view.
Command
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 ]
*
Command
system-view
bgp as-number
285
Remarks
Optional.
By default, no route
redistribution is configured.
Optional.
By default, BGP does not
filter the routes to be
advertised.
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.
Remarks
N/A
N/A