Juniper JUNOSE, Configuration Manual

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routes. If you associate an import map with a VRF, that VRF then accepts only
received routes that pass the import map (and match the import route target list).
import map
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Use to apply an import route map to a VRF to modify and filter routes imported
to the BGP RIB of the VRF from the global BGP VPN RIB in the parent VR.
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You can specify that only IPv4 or only IPv6 routes are imported. By default, both
types of routes are imported.
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Example
host1:boston(config-vrf)# import map routemap72
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Use the no version to remove the route map from the VRF.
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See import map.
Global Import Maps
Global import maps enable BGP routes to be imported from the global BGP non-VPN
RIB into the BGP RIB of a VRF based on a configured route map. You can use import
maps as an automated mechanism that enables a subset of the Internet to be
reachable from a VPN. This feature is intended to provide simplified central access
to a limited number of centralized services in the provider network. Use this feature
to import only a relatively small number (tens) of routes from the global domain into
the VPNs, such as a small number of routes to DNS servers, content servers,
management stations, and so on.
If instead you import the full Internet routing table into one or more VPNs, too much
memory will be consumed because this action stores multiple copies of the full
Internet routing table. To prevent an accidental misconfiguration, you must specify
the maximum number of routes to be imported into a VRF when you configure global
import. If you must provide access to the full Internet from a VPN, use the
fallback
global command.
global import map
■
Use to apply a route map to a VRF to modify and filter routes imported to the
BGP RIB of the VRF from the global BGP non-VPN RIB in the parent VR.
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You can specify that only IPv4 or only IPv6 routes are imported. By default, both
types of routes are imported.
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Use the max-routes keyword to specify the maximum number of routes that
you want to be imported into the local RIB. BGP generates a log message when
the specified number of routes has been imported; no additional routes are
imported.
WARNING 02/11/2005 10:28:35 bgpRoutes (default,10.13.5.21): Maximum
number of routes (5000) imported from global RIB into RIB of VRF foo.
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Changes to the maximum number of routes take effect immediately.
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Example
Configuring BGP VPN Services
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Chapter 5: Configuring BGP-MPLS Applications