global VPN RIB, they are not advertised to other PE routers. These imported routes are
never exported to the VRF RIBs of overlapping VPNs.
Routes that are exported from a VRF RIB to the global BGP non-VPN RIB with the global
export map are never imported back in to any VRF.
Routes that are imported from the global BGP VPN RIB (with an import map) into a VRF
RIB are never exported again.
Routes that are exported from a VRF RIB to the global VPN RIB can be imported into the
RIB of other VRFs. This behavior might be seen with overlapping VPNs.
Creating a Map
For information about creating a route map to be used as an import or export map, see
“Configuring BGP Routing” on page 3. The following example shows how to apply the
route map routemap5 to the VRF vpnA configured on the virtual router boston.
host1(config)#virtual router boston
host1:boston(config)#ip vrf vpnA
host1:boston(config-vrf)#import map routemap5
Export Maps
You can use an export map to change the attributes of a route when it is exported from
a VRF to the global BGP VPN RIB local to the VR. This RIB is often referred to as the core
VPN RIB. Export maps can optionally filter routes.
When the VRF route matches the export map, the route is exported and the attributes
are changed as specified in the export map.
When the VRF route does not match the export map, the filter keyword determines what
happens. If the filter keyword has been issued, then the route is not exported. If the filter
keyword has not been issued, then the route is exported but the attributes of the route
are not modified (because the export map was not matched).
If you do not configure an export map, then all routes are exported from the VRF to the
global BGP VPN RIB. However, routes that are imported into the VRF cannot be exported
again.
export map
• Use to apply a route map to a VRF to modify or filter routes exported from the VRF to
the global BGP VPN RIB in the parent VR.
• You can specify that only IPv4 or only IPv6 routes are exported. By default, both types
of routes are exported.
• Example
host1:boston(config-vrf)#export map routemap5 filter
• Use the no version to remove the route map from the VRF.
• See export map.
431Copyright © 2010, Juniper Networks, Inc.
Chapter 6: Configuring BGP-MPLS Applications
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