3Com MSR 50 Series Configuration Manual page 1487

For description and detailed configuration about IS-IS, refer to
■
Configuration" on page
Configuring EBGP between PE and CE
1 On a PE
Follow these steps to configure EBGP between PE and CE on a PE:
To do...
Enter system view
Enter BGP view
Enter BGP VPN instance view
Configure the CE as the VPN
peer
Inject the routes of the local
CEs
Configure BGP to filter routes
to be advertised
Configure BGP to filter
received routes
Allow the local AS number to
appear in the AS_PATH
attribute of a received route
and set the maximum number
of repetitions
n
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...
Enter system view
Enter BGP view
Configure the PE as the peer
Configuring Basic MPLS L3VPN
877.
Use the command...
system-view
bgp as-number
ipv4-family vpn-instance
vpn-instance-name
peer { group-name |
ip-address } as-number
as-number
import-route protocol
[ process-id ] [ 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
peer { group-name |
ip-address } allow-as-loop
[ number ]
Use the command...
system-view
bgp as-number
peer { group-name |
ip-address } as-number
as-number
1487
"IS-IS
Remarks
-
-
Required
Required
Required
A PE needs to inject the routes
of the local CEs into its VPN
routing table so that it can
advertise them to the peer PE.
Optional
By default, BGP does not filter
routes to be advertised.
Optional
By default, BGP does not filter
received routes.
Optional
For the hub and spoke
networking scheme
Remarks
-
-
Required