Juniper ACX1000 Configuration Manual page 901

Copyright © 2017, Juniper Networks, Inc.
determine what goes into the forwarding table. Because each instance is configured for
a particular VPN, each VPN has separate tables, rules, and policies that control its
operation. A separate VRF table is created for each VPN that has a connection to a
customer edge (CE) router. The VRF table is populated with routes received from directly
connected CE sites associated with the VRF routing instance, and with routes received
from other provider edge (PE) routers in the same VPN.
The standard or the global instance is called as the default routing instance. By default,
all interfaces are associated with the default routing instance and default routing
information base (RIB) (
inet0
default routing instance are also applicable to other routing instances.
A VRF routing instance is a BGP and MPLS VPN environment in which BGP is used to
exchange IP VPN routes and discover the remote site, and in which VPN traffic traverses
an MPLS tunnel in an IP and MPLS backbone. You can enable an ACX Series router to
function as a PE router by configuring VRF routing instances.
You can configure routing instances on ACX Series routers at the
routing-instance-name protocols]
IPv6, and multicast IPv6 address families. If you do not explicitly specify the address
family in an IPv4 or an IPv6 environment, the router is configured to exchange unicast
IPv4 or unicast IPv6 addresses by default. You can also configure the router to exchange
unicast IPv4 and unicast IPv6 routes in a specified VRF routing instance. If you specify
the multicast IPv4 or multicast IPv6 address family in the configuration, you can use BGP
to exchange routing information about how packets reach a multicast source, instead
of a unicast destination, for transmission to endpoints.
NOTE: Only the forwarding and virtual router routing instances support
unicast IPv6 and multicast IPv6 address families. Unicast IPv6 and multicast
IPv6 address families are not supported for VRF routing instances.
You can configure the following types of Layer 3 routing instances on ACX Series routers:
Forwarding—Use this routing instance type for filter-based forwarding applications.
For this instance type, there is no one-to-one mapping between an interface and a
routing instance. All interfaces belong to the default instance
forwarding tables and the selection of a table depends on the filter applied on the
interface.
Virtual router—A virtual router routing instance is similar to a VRF instance type, but is
used for non-VPN-related applications. There are no VRF import, VRF export, VRF
target, or route distinguisher requirements for this instance type. For this instance type,
there is a one-to-one mapping between an interface and a routing instance. This routing
instance type is used for routing and forwarding virtualization without VPNs (which is
achieved by using the VRF-Lite application).
VRF—Use the VRF routing instance type for Layer 3 VPN implementations. This routing
instance type has a VPN routing table as well as a corresponding VPN forwarding table.
For this instance type, there is a one-to-one mapping between an interface and a
routing instance. Each VRF routing instance corresponds with a forwarding table. The
). Routing options and routing policies supported on the
hierarchy level for unicast IPv4, multicast IPv4, unicast
Chapter 26: Configuring Layer 3 VPNs
[edit routing-instances
. There are multiple
inet.0
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