esigpri@SRLAB1# help topic logical-routers overview
OverviewLogical routers perform a subset of the actions of a physical router and
have their own unique routing tables, interfaces, policies, and routing
instances. A set of logical routers within a single router can handle the
functions previously performed by several small routers.The following are supported on logical routers:
* Open Shortest Path First (OSPF), Intermediate System-to-Intermediate
System (IS-IS), Routing Information Protocol (RIP), RIP next
generation (RIPng), Border Gateway Protocol (BGP), Resource
Reservation Protocol (RSVP), Label Distribution Protocol (LDP), static
routes, various multicast protocols, and Internet Protocol version 4
(IPv4) and version 6 (IPv6) are supported at the [edit logical-routers
protocols] hierarchy level.
* Basic Multiprotocol Label Switching (MPLS) for core provider router
functionality is supported at the [edit logical-routers protocols
mpls] hierarchy level.
* All policy-related statements available at the [edit policy-options]
hierarchy level are supported at the [edit logical-routers
policy-options] hierarchy level.
* Most routing options statements available at the [edit
routing-options] hierarchy level are supported at the [edit
logical-routers routing-options] hierarchy level. Only the
route-record statement is not supported at the [edit logical-routers
routing-options] hierarchy level.
* You can assign most interface types to a logical router, including
SONET interfaces, Ethernet interfaces, Asynchronous Transfer Mode
(ATM) interfaces, ATM2 interfaces, Channelized Q Performance Processor
(QPP) interfaces, aggregated interfaces, link services interfaces, and
multilink services interfaces.
* Source class usage, destination class usage, unicast reverse path
forwarding, class of service, firewall filters, class-based
forwarding, and policy-based accounting work with logical routers when
you configure these features on the physical router.
* Multicast protocols, such as Protocol Independent Multicast (PIM) and
Distance Vector Multicast Routing Protocol (DVMRP) are supported at
the [edit logical-routers logical-router-name protocols] hierarchy
The following restrictions apply to logical routers:
* You can configure a maximum of 15 logical routers on one physical
* The router has only one configuration file, which contains
configuration information for the physical router and all associated
logical routers. Master users can access the full configuration.
However, logical router users can access only the portion of the
configuration related to their particular logical router.
* All configuration commits performed by a logical router user are
treated as commit private. For more information on the commit private
command, see the JUNOS System Basics Configuration Guide.
* If a logical router experiences an interruption of its routing
protocol process (rpd), the core dump output is saved in a file in the
/var/tmp/rpd_logical-router-name.core-tarball.number.tgz. Likewise, if
you issue the restart routing command in a logical router, only the
routing protocol process (rpd) for the logical router is restarted.
* If you configure trace options for a logical router, the output log
file is stored in the following location:
* The following Physical Interface Cards (PICs) are not supported with
logical routers: Adaptive Services PIC, ES PIC, Monitoring Services
PIC, and Monitoring Services II PIC.
* Graceful Routing Engine switchover, sampling, port mirroring, IP
Security (IPSec), and Generalized MPLS (GMPLS) are not supported.
* Rendezvous point functionality for multicast protocols within a
logical router is not supported.
* Label-switched path (LSP) ping and traceroute for autonomous system
(AS) number lookup are not supported.
Logical Routers and Virtual Routers
A virtual router is not the same as a logical router. A virtual router is
a type of simplified routing instance that has a single routing table. A
logical router is a partition of a physical router and can contain
multiple routing instances and routing tables. For example, a logical
router can contain multiple virtual router routing instances.
esigpri@SRLAB1# help reference logical-routers logical-routers
Statement introduced before JUNOS Release 7.4.
Configure a logical router.
logical-router-name–Name of the logical router.
See “Logical Router Configuration Guidelines”.
Required Privilege Level
routing–To view this statement in the configuration.
routing-control–To add this statement to the configuration.