H3C Technologies H3C S7500E Series Switches - Manual (Page 22)

1-10
z
When the switch learns a VPN route from a site and injects it into BGP, BGP associates the
route with a VPN target extended community attribute list, which is normally the export route
attribute list of the VPN instance.
z
A VPN instance determines whether to accept a received route according to the VPN target
import extended community attribute list associated with the route and the setting specified by
the vpn-target command.
z
A VPN instance modifies the export VPN target attribute according to the setting specified by
the vpn-target command.
Follow these steps to configure the route-related attributes for a VPN instance:
To do… Use the command… Remarks
Enter system view system-view —
Enter VPN instance view
ip vpn-instance
vpn-instance-name
—
Associate the current VPN
instance with one or multiple VPN
targets
vpn-target vpn-target &<1-8>
[ both | export-extcommunity |
import-extcommunity ]
Required
By default, a VPN instance has no
VPN target associated with it.
Configure the maximum number
of routes a VPN instance can
accommodate
routing-table limit number
{ warn-threshold | simply-alert }
Optional
Not configured by default
Apply a route policy for the routes
received
import route-policy route-policy
Optional
By default, all routes matching the
VPN target attribute are permitted.
Apply a route policy for the routes
to be advertised
export route-policy route-policy
Optional
By default, all routes matching the
VPN target attribute are permitted.
z
Only when BGP runs between the MCE and PE, can the VPN target attribute be advertised to
the PE along with the routing information. In other cases, configuring this attribute makes no
sense.
z
VPN targets configured for a VPN instance on an MCE must be consistent with those
configured for the VPN instance on the PE.
z
You can define the maximum number of routes for a VPN instance to support, preventing too
many routes from being redistributed into the PE.
z
Before associating a routing policy with a VPN instance, you must create the routing policy at
first. Otherwise, the default routing policy is used.