Juniper BGP - CONFIGURATION GUIDE V 11.1.X

Figure 102: Fallback Global Option
If BGP finds a route in the VRF context, it uses that route. If BGP does not find a route
in the VRF context but does find a route in the VR context, it falls back on the global
route in the parent VR. BGP drops the packet if it does not find a route in either
context.
To enable fallback global on a PE-CE IP interface:
host1:pe1(config)#interface atm2/0.11
host1:pe1(config-if)#ip vrf forwarding pe11 fallback global
host1:pe1:pe11(config-if)#atm pvc 11 0 11 aal5snap
host1:pe1:pe11(config-if)#ip address 10.11.11.1 255.255.255.0
host1:pe1:pe11(config-if)#exit
See “Defining Secondary Routing Table Lookup” on page 434 for more information.
Configuring a Global Import Map for Specific Routes
For the third solution you create a global import map to import only the specific
routes needed to reach the desired small number of networks in the Internet. See
Figure 103 on page 465.
464 ■ Providing Internet Access to and from VPNs
JUNOSe 11.1.x BGP and MPLS Configuration Guide