Configuring Inter as Layer Two Circuit

8/16/2019 Configuring Inter as Layer Two Circuit

1/34

Network Configuration Example

Interconnecting Layer 2 Circuits Across ASBoundaries

Published: 2014-01-10

Copyright © 2014, Juniper Networks, Inc.


2/34

Juniper Networks, Inc.1194North Mathilda AvenueSunnyvale, California 94089USA408-745-2000www.juniper.net

Juniper Networks, Junos, Steel-Belted Radius, NetScreen, and ScreenOS are registered trademarks of Juniper Networks, Inc.in the UnitedStates and other countries. The Juniper Networks Logo, the Junos logo, and JunosE are trademarks of Juniper Networks, Inc.All othertrademarks, service marks, registered trademarks, or registered service marks are the property of theirrespective owners.

Juniper Networks assumes no responsibility for any inaccuracies in this document. Juniper Networks reserves the right to change, modify,transfer, or otherwise revise this publication without notice.

Network Configuration Example Interconnecting Layer 2 Circuits Across AS BoundariesNCE0093Copyright © 2014, Juniper Networks, Inc.All rights reserved.

The informationin this document is currentas of thedateon thetitlepage.

YEAR 2000 NOTICE

Juniper Networks hardware and software products are Year 2000 compliant. Junos OS has no known time-related limitations through theyear 2038. However,the NTPapplicationis known to have some difficulty in theyear2036.

END USER LICENSE AGREEMENT

The Juniper Networks product that is thesubject of this technical documentationconsists of (or is intended for usewith)Juniper Networkssoftware. Useof such software is subject to theterms and conditions of theEnd User License Agreement (“EULA”) posted athttp://www.juniper.net/support/eula.html . By downloading, installing or using such software, you agree to theterms and conditions ofthat EULA.

Copyright © 2014, Juniper Networks, Inc.ii

http://www.juniper.net/support/eula.htmlhttp://www.juniper.net/support/eula.html


3/34

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Use Case for Configuring Layer 2 Circuits Across AS Boundaries . . . . . . . . . . . . . . . 1Understanding the Operation of Layer 2 Circuits Across AS Boundaries . . . . . . . . . 2Introduction to Interconnecting Layer 2 Circuits Across Autonomous System

Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Understanding Layer 2 Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Autonomous Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Interconnecting Layer 2 Circuits Across Autonomous Systems . . . . . . . . . . . . 5

Example: Interconnecting Layer 2 Circuits Across Autonomous SystemBoundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

iiiCopyright © 2014, Juniper Networks, Inc.


4/34

Copyright © 2014, Juniper Networks, Inc.iv

Interconnecting Layer 2 Circuits Across AS Boundaries


5/34

Introduction

This document shows how to configureand verify an Inter-AS Layer2 circuit andexplainswhen this configuration might be useful.

Use Case for Configuring Layer 2 Circuits Across AS Boundaries

A Layer 2 circuit is a point-to-point Layer 2 connection transported using MultiprotocolLabel Switching (MPLS).

A Layer 2 circuit can transport traffic that originated from an ATM switch, Frame Relayswitch, or time division multiplexer as well as Ethernet switches.

The ability for a Layer 2 circuit to transport different types of traffic is an advantage toservice providers andtheir customers. This capability enables a service provider to betterutilize their core network infrastructure which reduces the cost of providing the transportservice

For customers it also reduces the complexity of the network by eliminating the need tooperate separate core networks for each type of Layer 2 traffic.

Furthermore the service provider core MPLS network can also transport Layer 3 VPNtraffic over the same infrastructure which also reduces the cost of providing services.

An inter-AS Layer 2 circuit extends the connection across multiple service providers thathave different autonomous system (AS) numbers.

An inter-AS Layer 2 circuit is useful when an enterprise has offices spread across a largegeographic area for example after a merger of two companies.

An inter-AS Layer 2 circuit forms a virtual Layer 2 network to transport traffic betweencustomer edge (CE) routers.

When a Layer 2 circuit is used to transport Ethernet traffic, the VLAN tagged Ethernetframes from the CE routers are encapsulated by the provider edge (PE) routers usingMPLS labels and the frames are switched across the service provider network.

For more information about the technical operation of an inter-AS Layer 2 circuit, seeUnderstanding the Operation of Layer 2 Circuits Across AS Boundaries .

RelatedDocumentation

Example: Interconnecting Layer 2 Circuits Across Autonomous System Boundaries onpage 5

•

• Introductionto InterconnectingLayer 2 CircuitsAcross Autonomous System Boundariesonpage 4

• Understanding the Operation of Layer 2 Circuits Across AS Boundaries on page 2

1Copyright © 2014, Juniper Networks, Inc.


6/34

Understanding the Operation of Layer 2 Circuits Across AS Boundaries

A Layer 2 circuit is a point-to-point Layer 2 connection transported using MultiprotocolLabel Switching (MPLS).

An inter-AS Layer 2 circuit offers the ability to extend the reach of Layer 2 connectionsacross multiple service providers.

In Figure 1 an inter-AS Layer 2 circuit forms a virtual layer-2 network to transport VLANtagged Ethernet frames between customer edge (CE) routers.

Figure 1: Operation of a Layer 2 Circuit Across AS Boundaries

The CE routers are transmitting VLAN tagged Ethernet frames.

The PE routers are configured to support:

• VLAN tagged Ethernet on the logical interfaces connected to the CE routers.

• A Layer 2 circuit service for the CE router. (creates the virtual circuit label and bindsthe PE interface with the label)

• OSPF as the IGP between the PE router and the ASBR.

• MPLS switching between the PE router and the ASBR.

• RSVP signaling between the PE router and the ASBR.

• An IBGP peer session between the PE router and the ASBR.

• A loopback interface with an IPv4 addresses using a /32 subnet mask.

Copyright © 2014, Juniper Networks, Inc.2



7/34

The ASBR routers are configured to support:

• OSPF as the IGP between the PE router and the ASBR.

• MPLS switching between the PE router and the ASBR.



• MPLS between the ASBR and the remote ASBR.

• An EBGP peer session between the PE router and the ASBR.

An RSVP-TE LSP is established between the PE router and the ASBR router.

RFC 3107 describes the method, known as labeled unicast routes, to use MBGP to carrylabels with routing information. Labeled unicast routes are unicast routes with an MPLSlabel binding (a prefix and label).

An EBGP peer session is established between the ASBRs. The ASBRs announce labeledunicast routes to each other for the /32 routes to the PE routers in their local AS. Theroutes are advertised with the ASBR identifying itself as the next hop.

The ASBR then advertises the route it learned from the peer ASBR to the PE router in itslocal AS.

The PE routers are configured to support targeted LDP sessions between the PE routers.

Targeted LDP is used for inner label distribution to distribute the pseudowire (virtualcircuit) labels that enables the Layer 2 circuit. This extends the LSP from the ingress PErouter to the egress PE router.

TIP: Targeted LDP sessions are different than non-targeted LDP sessionsbecause duringthe discovery phase hellos are unicast to the LDPpeer ratherthan being multicast to all routers. A consequence of this is that targetedLDPcanbe usedbetween non-directlyconnected peerswhereas non-targetedLDP peers must be on the same subnet.

An Inter-AS Layer 2 circuit is established across the ASs.

When a packet traverses the ASBR it has the following three labels:

• The RSVP label for the IGP next-hop

• The MBGP label

• The targeted LDP label for the Layer 2 circuit

Since LSPs are unidirectional, a bidirectional Layer 2 circuit requires two LSPs. The sameprocess is used to create the LSP in the reverse direction.


Example: Interconnecting Layer 2 Circuits Across Autonomous System Boundaries onpage 5

•



8/34


• Use Case for Configuring Layer 2 Circuits Across AS Boundaries on page 1

IntroductiontoInterconnecting Layer2 CircuitsAcrossAutonomousSystemBoundaries

Thefollowing sections explain about Layer2 circuits andhow you caninterconnect Layer2 circuits across autonomous system boundaries in detail:

• Understanding Layer 2 Circuit on page 4

• Autonomous Systems on page 5

• Interconnecting Layer 2 Circuits Across Autonomous Systems on page 5

Understanding Layer 2 Circuit

A Layer 2 circuit is a point-to-point Layer 2 connection transported using eitherMultiprotocol Label Switching (MPLS) technology or any other tunneling technology ona service provider network. A Layer 2 circuit is similar to a circuit cross-connect (CCC),except that multiple virtual circuits (VCs) are transported over a single sharedlabel-switched path (LSP) tunnel between two provider edge (PE) routers. In contrast,eachCCCrequiresa separatededicated LSP. For more information aboutLayer 2 circuits,see Layer 2 Circuits Overview .

The following occurs to establish a Layer 2 circuit:

1. Firstly, Link Integrity Protocol (LIP) is used as the signaling protocol to advertise theingress label to the remote PE routers.

2. To advertise the ingress label, a targeted remote Label Distribution Protocol (LDP)neighbor session is established using the extended discovery mechanism describedin LDP, and the session is brought up on the remote PE loopback interface IP address.

Since, LDP looks at the Layer 2 circuit configuration and initiates extended neighbordiscovery for all the Layer 2 circuit neighbors (the remote PEs), no new configurationis necessary in LDP.

3. Each Layer 2 circuit is represented by the logical interface connecting the local PErouter to the local customer edge (CE) router. Therefore, LDP must be enabled onthe lo0.0 loopback interface for extended neighbor discovery to function correctly.

4. Packets are then sent to remote CE routers over an egress VPN label advertised bythe remote PE router, using a targeted LDP session.

5. The VPN label is sent over an LDP LSP tothe remote PE router connected totheremote CE router.

6. Return traffic from the remote CE router destined to the local CE router is sent usingan ingress VPN label advertised bythe local PE router, whichis also sent over the LDPLSP to the local PE router from the remote PE router.



http://www.juniper.net/techpubs/en_US/junos/topics/concept/layer-two-circuits-overview-solutions.htmlhttp://www.juniper.net/techpubs/en_US/junos/topics/concept/layer-two-circuits-overview-solutions.html


9/34

For information aboutconfiguring interfaces forLayer2 circuits, see Configuring Interfacesfor Layer 2 Circuits .

Autonomous Systems

Layer 2 circuits are configured between two peers. The peers must use the same interiorgateway protocol (IGP), such as Open Shortest Path First (OSPF) or IntermediateSystem-to-Intermediate System (IS-IS). Also, the peers must have asymmetrical Layer2 configuration and belong to the same routing domain or autonomous system (AS).

An autonomous system (AS) is a set of routing devices that are under a single technicaladministration andthatgenerally use a single interiorgateway protocol (IGP) andmetricstopropagate routing information withinthe setof routing devices. An ASappearsto otherASs to have a single, coherent interior routing plan and presents a consistent picture ofwhat destinationsare reachablethroughit. ASsare identified by a number thatis assignedby the Network Information Center (NIC) in the United States. If you are using BGP on arouting device, youmust configurean ASnumber. Formoreinformationaboutautonomous

systems and assigning an AS number, see autonomous-system .

Interconnecting Layer 2 Circuits Across Autonomous Systems

To interconnect a Layer 2 circuit across two autonomous systems, you must configureexternal BGP and Layer 2 circuits with the vpn-ccc encapsulation on the provider edge(PE) routers and configure therouters with a VLAN ID that is thesameacross all the PEsthat are configured with the Layer 2 circuit. You must also configure internal BGP, RSVP,and an LDP tunnel between the AS boundary router and the PE router. The “Example:Interconnecting Layer 2 Circuits Across Autonomous System Boundaries” on page 5topic explains in detail how to interconnect Layer 2 Circuits across two autonomoussystems.


Understanding the Operation of Layer 2 Circuits Across AS Boundaries on page 2•


Example: Interconnecting Layer 2 Circuits Across Autonomous System Boundaries

This example describes how to interconnect and configure Layer 2 circuits acrossautonomous systems (AS).

This example is organized in the following sections:

• Requirements on page 6

• Overview and Topology on page 6• Configuration on page 7



10/34

Requirements

To interconnect and configure Layer 2 circuits across AS, your network must meet the

following hardware and software requirements:• M Series Multiservice Edge Routers, MX Series 3D Universal Edge Routers, or T Series

Core Routers.

• Junos OS Release 10.4 or higher.

NOTE: Thisconfiguration examplehasbeentestedusingthe software releaselisted and is assumed to work on all later releases.

Overview and Topology

To interconnect a Layer 2 circuit across two autonomous systems, you must configurethe following:

• On customer edge (CE) routers:

• Loopback interface.

• Ethernet interface connecting the CE router to the PE router.

• On provider edge (PE) routers:


• Ethernet interfaces connecting the PE router to the CE router and to the ASBR.

•

OSPF as the IGP between the PE router and the ASBR with the area set as 0.0.0.0.• MPLS switching where an LSP is enabled for LDP tunneling



• Targeted LDP by configuring strict-targeted-hellos and l2-smart-policy statements.

• A Layer 2 circuit service for the CE router (creates the virtual circuit label and bindsthe PE interface with the label).

• On AS boundary routers (ASBRs):


• Ethernet interface and logical interfaces connecting the ASBRs and PE routers.

• OSPF as the IGP between the PE router and the ASBR with area set as 0.0.0.0.

• MPLS switching where LSP is enabled for LDP tunneling.





11/34


• An EBGP peer session between the ASBRs.

NOTE: The topology shown in Figure 2 on page 7 has been configured byusing logical systems with a combination of physical interfaces and logicaltunnel (lt) interfaces. You can configure this topology using only physicalinterfaces as well.

Figure 2 on page 7 shows the topology used in this example.

Figure 2: Interconnecting Layer 2 Circuits Across Autonomous SystemExample Topology Example Topology

Configuration

To configure Layer 2 circuits across AS boundaries, perform these tasks:

NOTE: In any configuration session it is a good practice to periodically usethe commitcheck command to verifythat the configuration canbe committed.

• Configuring Logical Systems on page 8

• Configuring Interfaces on page 9

• Configuring OSPF on page 11

• Configuring RSVP on page 12

• Configuring LDP on page 12

• Configuring MPLS on page 13

• Configuring Internal BGP on page 14

• Configuring Policy Options on page 15

• Configuring External BGP on page 16

• Configuring Layer 2 Circuit Between PE Routers on page 19

• Results on page 22



12/34

Configuring Logical Systems

Step-by-StepProcedure

The following example requires you to navigate various levels in the configurationhierarchy. Forinformation about navigatingthe CLI,see Using theCLI Editor in ConfigurationMode in the CLI User Guide .

To verify if your router supports logical tunnel (lt) interfaces and to create and navigateto a logical system, perform the following steps:

• Run the show interfaces terse command to verify that the physical router has alogical tunnel ( lt ) interface.

user@host> showinterfaces terseInterface Admin Link Proto Local Remote...lt-2/0/10 up up...

•

Navigate to configuration mode to create a logical system (for example, CE1) andcommit.

[edit]user@host# set logical-system CE1user@host# commit

Create similar logical systems for PE1, ASBR1, ASBR2, PE2, and CE2 routers.

• To edit a logical system. For example, CE1 logical system:

user@host> set cli logical-system CE1Logical system: CE1

user@host:CE1>

user@host:CE1> edit

[edit]user@host:CE1#

For more information about logical systems, see Examples: Configuring Logical System Interfaces .

NOTE: In logical systems, you must treat each interface like apoint-to-point connection because you can only connect one logical

tunnel interface to another at any given time. Also, you must select aninterface encapsulation type, specify a DLCI number or VLAN identifier,configure a corresponding protocol family, and set the logical interfaceunit number of the peering lt interface.

• To exit a logical system. For example, CE1 logical system:

[edit]user@host:CE1# exit




13/34

Exiting configuration mode

user@host:CE1> clear cli logical-systemCleared default logical system

user@host>

Configuring Interfaces


To configure interfaces and to verify the configuration with the show interfaces lo0 andshow interfaces terse operational mode commands, perform the following steps:

1. Configure an IP address on the loopback logical interface (lo0) on each logicalsystem:

user@host:CE1# set logical-systems CE1 interfaces lo0 unit 1 family inet address192.168.0.1/32

user@host:PE1# set logical-systems PE1 interfaces lo0 unit 2 family inet address192.168.0.2/32

user@host:ASBR1# set logical-systems ASBR1 interfaces lo0 unit 3 family inetaddress 192.168.0.3/32

user@host:ASBR2# set logical-systems ASBR2 interfaces lo0 unit 4 family inetaddress 192.168.0.4/32

user@host:PE2# set logical-systems PE2 interfaces lo0 unit 5 family inet address192.168.0.5/32

user@host:CE2# set logical-systems CE2 interfaces lo0 unit 6 family inet address192.168.0.6/32

2. Commit the configuration:

user@host:CE1# commit checkconfiguration check succeedsuser@host:CE1# commitcommit complete

3. Display the interface information for the lo0 loopback interface and verify that thecorrect IP address is configured:

user@host:ASBR2> show interfaces lo0Physical interface: lo0

Logical interface lo0.4 (Index 355) (SNMP ifIndex 623) Flags: SNMP-Traps Encapsulation: Unspecified Input packets : 0 Output packets: 0 Protocol inet, MTU: Unlimited Flags: Sendbcast-pkt-to-re Addresses, Flags: Is-Default Is-Primary Local: 192.168.0.4



14/34

In the example above notice that the loopback interface local address for the inetprotocol family on logical system ASBR2 is 192.168.0.4.

4. Configure an IP address, protocol family as inet , VLAN tagging, and VLAN ID on the

physical Ethernet interface connecting the CE1 router to the PE1 router.user@host# set interfaces ge-2/0/6 vlan-tagging unit 600 description “to-PE1”

vlan-id 600 family inet address 172.16.1.2/24

5. Configure VLANtagging, VLANCCC encapsulation on thephysical Ethernet interfaceand the logical interface connecting the PE1 router to the CE1 router and specify theccc protocol family and VLAN ID. Configure an IP address, peer unit and specifyencapsulation as ethernet and the protocol family as inet on the logical tunnelinterface connecting PE1 router to ASBR1 router.

user@host:PE1# set interfaces ge-2/1/0 vlan-tagging encapsulation vlan-ccc unit600 description “to CE1” encapsulation vlan-ccc vlan-id 600 family ccc

user@host:PE1# set interfaceslt-2/0/10 unit5 description“to-ASBR1”encapsulationethernet peer-unit 6 family inet address 10.0.0.5/30

6. Configure an IP address, peer unit, and specify the protocol family as inet andencapsulation as ethernet on the logical tunnel interfaces connecting the ASBR1router to the PE1 router and to the ASBR2 router.

user@host:ASBR1# set interfaces lt-2/0/10 unit6 descriptionto-PE1 encapsulationethernet peer-unit 5 family inet address 10.0.0.6/30

user@host:ASBR1# set interfaces lt-2/0/10 unit 9 description to-ASBR2encapsulation ethernet peer-unit 10 family inet address 10.0.0.9/30

7. Configure an IP address, protocol family as inet on the physical Ethernet interfaceconnecting the ASBR2 router to the PE2 router. Configure an IP address, protocolfamily as inet , encapsulationas ethernet andpeerunit onthe logical tunnelinterfaceconnecting the ASBR2 router to the ASBR1 router.

user@host:ASBR2# set interfaces ge-2/0/9 unit 0 description to-PE2 family inetaddress 10.0.0.13/30

user@host:ASBR2# set interfaces lt-2/0/10 unit 10 description to-ASBR1encapsulation ethernet peer-unit 9 family inet address 10.0.0.10/30

8. Configure VLANtagging, VLANCCC encapsulation on thephysical Ethernet interfaceand the logical interface connecting the PE2 router to the CE2 router and specifythe ccc protocol family and VLAN ID. Configure an IP address, protocol family asinet on the physical Ethernet interface connecting the PE2 router to the ASBR2router.

user@host# set interfaces ge-2/1/1 vlan-tagging encapsulation vlan-ccc unit 600description “to CE2” encapsulation vlan-ccc vlan-id 600 family ccc

user@host:PE2# set interfaces ge-2/1/3 unit 0 description to-ASBR2 family inetaddress 10.0.0.14/30

9. Configure an IP address, protocol family as inet , VLAN tagging, and VLAN ID on thephysical Ethernet interface connecting the CE2 router to the PE2 router.

user@host# set interfaces ge-2/1/2 vlan-tagging unit 600 description “to-PE2”vlan-id 600 family inet address 172.16.1.1/24


user@host:CE1# commit check




15/34

configuration check succeedsuser@host:CE1# commitcommit complete

11. Display information for Gigabit Ethernet interfaces and verify that the IP address

and protocol family are configured correctly.user@host:ASBR2> show interfaces terseInterface Admin Link Proto Local Remotege-2/0/9ge-2/0/9.0 up up inet 10.0.0.13/30lt-2/0/10lt-2/0/10.10 up up inet 10.0.0.10/30lo0lo0.4 up up inet 192.168.0.4 --> 0/0

Configuring OSPF


To configure OSPF andto verify if theconfiguration is working with the showospf neighboroperational mode command, perform the following steps:

1. On the PE and ASBR logical systems, configure the provider instance of OSPF.Configure OSPF traffic engineering support. Specify area 0.0.0.0 and specify theEthernet logical interfaces between the PE and ASBR routers. Specify lo0.0 as apassive interface for OSPF.

user@host:PE1# set protocols ospf traffic-engineeringuser@host:PE1# set protocols ospf area 0.0.0.0 interface lt-2/0/10.5user@host:PE1# set protocols ospf area 0.0.0.0 interface lo0.2 passive

user@host:ASBR1# set protocols ospf traffic-engineeringuser@host:ASBR1# set protocols ospf area 0.0.0.0 interface lt-2/0/10.6user@host:ASBR1# set protocols ospf area 0.0.0.0 interface lo0.3 passive

user@host:ASBR2# set protocols ospf traffic-engineeringuser@host:ASBR2# set protocols ospf area 0.0.0.0 interface ge-2/0/9.0user@host:ASBR2# set protocols ospf area 0.0.0.0 interface lo0.4 passive

user@host:PE2# set protocols ospf traffic-engineeringuser@host:PE2# set protocols ospf area 0.0.0.0 interface ge-2/1/3.0user@host:PE2# set protocols ospf area 0.0.0.0 interface lo0.5passive


user@host:PE1# commit checkconfiguration check succeedsuser@host:PE1# commit

commit complete3. Display OSPF neighbor information and verify that the PE routers form adjacencieswith the ASBR router in the same area. Verify that the neighbor state is Full .

user@host:ASBR2> show ospf neighbor

Address Interface State ID Pri Dead10.0.0.14 ge-2/0/9.0 Full 192.168.0.5 128 34



16/34

Configuring RSVP


To configure RSVP signaling between the PE router and the ASBR and to verify if theconfigurationis workingwith the showrsvpneighbor operationalmodecommand, performthe following steps:

1. On the PE routers and the ASBRs, configure RSVP:

user@host:PE1# set protocols rsvp interface lo0.2user@host:PE1# set protocols rsvp interface lt-2/0/10.5;

user@host:ASBR1# set protocols rsvp interface lo0.3user@host:ASBR1# set protocols rsvp interface lt-2/0/10.6

user@host:ASBR2# set protocols rsvp interface lo0.4user@host:ASBR2# set protocols rsvp interface ge-2/0/9.0

user@host:PE2# set protocols rsvp interface lo0.5user@host:PE2# set protocols rsvp interface ge-2/1/3.0


user@host:PE1# commit checkconfiguration check succeedsuser@host:PE1# commitcommit complete

3. Display RSVP neighbor information and verify that the PE routers form adjacencieswith the ASBR in the same area.

user@host:ASBR2> show rsvpneighborRSVP neighbor: 1 learnedAddress Idle Up/Dn LastChange HelloInt HelloTx/Rx MsgRcvd

10.0.0.14 10 1/0 1d 15:20:18 9 15658/15658 6307

Configuring LDP


To configure targeted LDP on PE routers and to verify if the configuration is working withthe showconfiguration protocols ldp operational mode command, perform the followingsteps:

1. On the PE routers and the ASBRs,enableLDP between the PE router and theASBR,and between the two ASBRs. Include the strict-targeted-hellos statement in the PErouter configuration. The strict-targeted-hellos statement is what enables the PErouters to unicast hello messages to the non-directly connected LDP peer ratherthan multicast the hello messages to all routers.

user@host:PE1# set protocols ldp l2-smart-policyuser@host:PE1# set protocols ldp strict-targeted-hellosuser@host:PE1# set protocols ldp interface lo0.2user@host:PE1# set protocols ldp session 192.168.0.5 authentication-key

"$9$tt8Tu1hleWNVwSylM8Xws5QF3/t1IcvWxSrxdsYZGDikqT30ORevLO1WLNV4oDik.z6";## SECRET-DATA

user@host:ASBR1# set protocols ldp interface lo0.3




17/34

user@host:ASBR2# set protocols ldp interface lo0.4

user@host:PE2# set protocols ldp l2-smart-policyuser@host:PE2# set protocols ldp strict-targeted-hellos

user@host:PE2# set protocols ldp interface lo0.5user@host:PE2# set protocols ldp session 192.168.0.2 authentication-key

"$9$h8OSeW7Nb4JGLX7VwYGUCtu01heK8db2Lx2aUDmP5QF3A0yrvNdsrebs4JHk5QFnpB";## SECRET-DATA



3. Display LDP configuration information and verify that the correct interfaces areconfigured. LDP operation can be verified after MPLS is configured.

user@host:ASBR2> show configuration protocols ldp

interface lo0.4;

Configuring MPLS


To configure MPLS and to verify if the configuration is working, perform the followingsteps:

1. On the PE routers and the ASBRs, configure MPLS by enabling MPLS on the logicalinterfaces, add the Ethernet interfaces to the MPLS protocol, and create the LSPbetween the PE routers and the ASBRs. Adding the Ethernet interfaces createsentries in the MPLS forwarding table.

user@host:PE1# set protocols mpls no-cspfuser@host:PE1# set protocols mpls label-switched-path PE1-ASBR1 to 192.168.0.3

ldp-tunnelinguser@host:PE1# set protocols mpls interface lt-2/0/10.5user@host:PE1# set interfaces lt-2/0/10 unit 5 family mpls

user@host:ASBR1# set protocols mpls no-cspf label-switched-path ASBR1-to-PE1to 192.168.0.2 ldp-tunneling

user@host:ASBR1# set protocols mpls interface lt-2/0/10.6user@host:ASBR1# set interfaces lt-2/0/10 unit 6 family mplsuser@host:ASBR1# set interfaces lt-2/0/10 unit 9 family mpls

user@host:ASBR2# set protocolsmpls no-cspf label-switched-pathASBR2-to-PE2to 192.168.0.5 ldp-tunneling

user@host:ASBR2# set protocols mpls interface ge-2/0/9.0user@host:ASBR2# set interfaces ge-2/0/9 unit 0 family mplsuser@host:ASBR2# set interfaces lt-2/0/10 unit 10 family mpls

user@host:PE2# set protocols mpls no-cspfuser@host:PE2# set protocols mpls label-switched-path PE2-to-ASBR2 to

192.168.0.4 ldp-tunnelinguser@host:PE2# set protocols mpls interface ge-2/1/3.0user@host:PE2# set interfaces ge-2/1/3 unit 0 family mpls



18/34



3. On the PE routers and the ASBRs, display LDP neighbor information and verify thatthe directly connected and indirectly-connected LDP neighbors are listed:

user@host:ASBR1> show ldp neighborAddress Interface Label space ID Hold time192.168.0.5 lo0.4 192.168.0.5:0 42

user@host:PE2> showldp neighborAddress Interface Label space ID Hold time192.168.0.4 lo0.5 192.168.0.4:0 44

Configuring Internal BGP

Step-by-StepProcedure To configure the routing options and internal BGP (IBGP) on PE routers and on ASBRs,perform the following steps:

1. On PE routers and ASBRs, configure an autonomous system number:

user@host:PE1# set routing-options autonomous-system 64510

user@host:ASBR1# set routing-options autonomous-system 64510

user@host:ASBR2# set routing-options autonomous-system 64511

user@host:PE2# set routing-options autonomous-system 64511

2. Configure IBGP on PE1:

user@host:PE1# set protocols bgp group int type internal local-address 192.168.0.2family inet unicast

user@host:PE1# set protocols bgp group int family inet labeled-unicast rib inet.3user@host:PE1# set protocols bgp group int neighbor 192.168.0.3

3. Configure IBGP on ASBR1:

user@host:ASBR1# setprotocolsbgpgroupint typeinternal local-address192.168.0.3family inet unicast

user@host:ASBR1# setprotocolsbgpgroupint typeinternal local-address192.168.0.3family inet labeled-unicast rib inet.3

user@host:ASBR1# set protocols bgp group int neighbor 192.168.0.2user@host:ASBR1# set protocols bgp group int export next-hop-self

4. Configure IBGP on ASBR2:user@host:ASBR2# set protocols bgp group int type internal local-address

192.168.0.4 family inet unicastuser@host:ASBR2# set protocols bgp group int type internal local-address

192.168.0.4 family inet labeled-unicast rib inet.3user@host:ASBR2# set protocols bgp group int neighbor 192.168.0.5user@host:ASBR2# set protocols bgp group int export next-hop-self

5. Configure IBGP on PE2:




19/34

user@host:PE2# set protocolsbgp groupint typeinternal local-address 192.168.0.5family inet unicast

user@host:PE2# set protocolsbgp groupint typeinternal local-address 192.168.0.5family inet labeled-unicast rib inet.3

user@host:PE2# set protocols bgp group int neighbor 192.168.0.4;

Configuring Policy Options


To configure the policy options on ASBRs:

Create the next-hop-self policy on ASBR router1. The next-hop-self policy is whatenables the ASBRs to announce labeled unicast routes to each other for the /32

1.

routes to the PE routers in their local AS. The routes are advertised with the ASBRidentifying itself as the next hop.

user@host:ASBR1# set policy-options policy-statement next-hop-self term 1 thennext-hop self

2. Create the send-pe policy on ASBR1 router. The send-pe policy is what enables theASBRs to advertise the route it learned from the peer ASBR to the PE router in itslocal AS.

user@host:ASBR1# set policy-options policy-statement send-pe from route-filter192.168.0.2/32 exact

user@host:ASBR1# set policy-options policy-statement send-pe then accept

3. Create the next-hop-self policy on ASBR2 router. The next-hop-self policy is whatenables the ASBRs to announce labeled unicast routes to each other for the /32routes to the PE routers in their local AS. The routes are advertised with the ASBRidentifying itself as the next hop.

user@host:ASBR2# set policy-options policy-statement next-hop-self term 1 then

next-hop self4. Create the send-pe policy on ASBR2 router. The send-pe policy is what enables the

ASBRs to advertise the route it learned from the peer ASBR to the PE router in itslocal AS.

user@host:ASBR2# set policy-options policy-statement send-pe from route-filter192.168.0.5/32 exact

user@host:ASBR2# set policy-options policy-statement send-pe then accept


user@host:ASBR1# commit checkconfiguration check succeedsuser@host:ASBR1# commitcommit complete



20/34

Configuring External BGP


On the ASBRs, configure external BGP (EBGP) with labeled unicast routes and specifythe inet.3 routing table. Including the labeled-unicast statement is what enables theASBRs to use MBGP to carry labeled unicast routes with an MPLS label binding (a prefixand label). Verify it with the show bgp neighbor , show bgp summary , and the show bgpgroup operational mode commands.

1. Configure EBGP on ASBR1:

user@host:ASBR1# set protocols bgp group ext type external family inet unicastuser@host:ASBR1# set protocols bgp group ext type external family inet

labeled-unicast rib inet.3user@host:ASBR1# set protocols bgp group ext export send-peuser@host:ASBR1# set protocols bgp group ext peer-as 64511user@host:ASBR1# set protocols bgp group ext neighbor 10.0.0.10

2. Configure EBGP on ASBR2:

user@host:ASBR2# set protocols bgp group ext type external family inet unicastuser@host:ASBR2# set protocols bgp group ext type external family inet

labeled-unicast rib inet.3user@host:ASBR2# set protocols bgp group ext export send-peuser@host:ASBR2# set protocols bgp group ext peer-as 64510user@host:ASBR2# set protocols bgp group ext neighbor 10.0.0.9


user@host:ASBR1# commit checkconfiguration check succeedsuser@host:ASBR1# commitcommit complete

4. Display BGP neighbors using the show bgp neighbor operational mode command.

user@host:PE2> showbgp neighborPeer: 192.168.0.4+50790 AS 64511 Local: 192.168.0.5+179 AS 64511 Type: Internal State: Established Flags: Last State: OpenConfirm Last Event: RecvKeepAlive Last Error: Cease Options: Address families configured: inet-unicast inet-labeled-unicast Local Address: 192.168.0.5 Holdtime: 90 Preference: 170 Number of flaps: 1 Last flap event: Stop Error: 'Cease' Sent: 1 Recv: 0 Peer ID: 192.168.0.4 Local ID: 192.168.0.5 Active Holdtime: 90 Keepalive Interval: 30 Group index: 1 Peer index: 0

BFD: disabled, down NLRI for restart configured on peer: inet-unicast inet-labeled-unicast NLRI advertised by peer: inet-unicast inet-labeled-unicast NLRI for this session: inet-unicast inet-labeled-unicast Peer supports Refresh capability (2) Stale routes from peer are kept for: 300 Peer does not support Restarter functionality NLRI that restart is negotiated for: inet-unicast inet-labeled-unicast NLRI of received end-of-rib markers: inet-unicast inet-labeled-unicast NLRI of all end-of-rib markers sent: inet-unicast inet-labeled-unicast Peer supports 4 byte AS extension (peer-as 64511) Peer does not support Addpath




21/34

Table inet.0 Bit: 10000 RIB State: BGP restart is complete Send state: in sync Active prefixes: 1 Received prefixes: 1 Accepted prefixes: 1 Suppressed due to damping: 0 Advertised prefixes: 0 Table inet.3 Bit: 20000 RIB State: BGP restart is complete Send state: in sync Active prefixes: 1 Received prefixes: 1 Accepted prefixes: 1 Suppressed due to damping: 0 Advertised prefixes: 0 Last traffic (seconds): Received 5 Sent 18 Checked 20

Input messages: Total 5163 Updates 6 Refreshes 0 Octets 98319

Output messages: Total 5186 Updates 4 Refreshes 0 Octets 98758

Output Queue[0]: 0 Output Queue[1]: 0

5. On ASBR2router, display theBGP summaryinformationusing the showbgpsummaryoperational mode command. Verify that the state of each peer is Established .

user@host:ASBR2> show bgp summaryPeer: 10.0.0.9+179 AS 64510 Local: 10.0.0.10+52476 AS 64511 Type: External State: Established Flags: Last State: OpenConfirm Last Event: RecvKeepAlive Last Error: Cease Export: [ send-pe ]

Options: Address families configured: inet-unicast inet-labeled-unicast Holdtime: 90 Preference: 170 Number of flaps: 1 Last flap event: Stop Error: 'Cease' Sent: 1 Recv: 0 Peer ID: 192.168.0.3 Local ID: 192.168.0.4 Active Holdtime: 90 Keepalive Interval: 30 Group index: 2 Peer index: 0

BFD: disabled, down Local Interface: lt-2/0/10.10

NLRI for restart configured on peer: inet-unicast inet-labeled-unicast NLRI advertised by peer: inet-unicast inet-labeled-unicast NLRI for this session: inet-unicast inet-labeled-unicast Peer supports Refresh capability (2) Stale routes from peer are kept for: 300 Peer does not support Restarter functionality NLRI that restart is negotiated for: inet-unicast inet-labeled-unicast NLRI of received end-of-rib markers: inet-unicast inet-labeled-unicast NLRI of all end-of-rib markers sent: inet-unicast inet-labeled-unicast Peer supports 4 byte AS extension (peer-as 64510) Peer does not support Addpath Table inet.0 Bit: 10001 RIB State: BGP restart is complete Send state: in sync Active prefixes: 1 Received prefixes: 1 Accepted prefixes: 1 Suppressed due to damping: 0



22/34

Advertised prefixes: 1 Table inet.3 Bit: 20001 RIB State: BGP restart is complete Send state: in sync Active prefixes: 1 Received prefixes: 1 Accepted prefixes: 1 Suppressed due to damping: 0 Advertised prefixes: 1 Last traffic (seconds): Received 12 Sent 27 Checked 30




Peer: 192.168.0.5+179 AS 64511 Local: 192.168.0.4+50790 AS 64511 Type: Internal State: Established Flags: Last State: OpenConfirm Last Event: RecvKeepAlive

Last Error: None Export: [ next-hop-self ]

Options: Address families configured: inet-unicast inet-labeled-unicast Local Address: 192.168.0.4 Holdtime: 90 Preference: 170 Number of flaps: 1 Last flap event: RecvNotify Error: 'Cease' Sent: 0 Recv: 1 Peer ID: 192.168.0.5 Local ID: 192.168.0.4 Active Holdtime: 90 Keepalive Interval: 30 Group index: 1 Peer index: 0

BFD: disabled, down NLRI for restart configured on peer: inet-unicast inet-labeled-unicast NLRI advertised by peer: inet-unicast inet-labeled-unicast NLRI for this session: inet-unicast inet-labeled-unicast Peer supports Refresh capability (2)

Stale routes from peer are kept for: 300 Peer does not support Restarter functionality NLRI that restart is negotiated for: inet-unicast inet-labeled-unicast NLRI of received end-of-rib markers: inet-unicast inet-labeled-unicast NLRI of all end-of-rib markers sent: inet-unicast inet-labeled-unicast Peer supports 4 byte AS extension (peer-as 64511) Peer does not support Addpath Table inet.0 Bit: 10000 RIB State: BGP restart is complete Send state: in sync Active prefixes: 0 Received prefixes: 0 Accepted prefixes: 0 Suppressed due to damping: 0 Advertised prefixes: 1 Table inet.3 Bit: 20000 RIB State: BGP restart is complete Send state: in sync Active prefixes: 0 Received prefixes: 0 Accepted prefixes: 0 Suppressed due to damping: 0 Advertised prefixes: 1 Last traffic (seconds): Received 3 Sent 19 Checked 74





23/34



6. On PE2 router, display BGPgroupinformationusing the show bgpgroup operationalmode command. Verify that the state of each peer is Established .

user@host:PE2> show bgpgroupGroup Type: Internal AS: 64511 Local AS: 64511 Name: int Index: 1 Flags: Export: [ next-hop-self ]

Holdtime: 0 Total peers: 1 Established: 1 192.168.0.5+179 inet.0: 0/0/0/0 inet.3: 0/0/0/0

Group Type: External Local AS: 64511 Name: ext Index: 2 Flags:

Export: [ send-pe ]Holdtime: 0 Total peers: 1 Established: 1 10.0.0.9+179 inet.0: 1/1/1/0 inet.3: 1/1/1/0

Groups: 2 Peers: 2 External: 1 Internal: 1 Down peers: 0 Flaps: 2Table Tot Paths Act Paths Suppressed History Damp StatePendinginet.0

1 1 0 0 00

inet.31 1 0 0 0

0

Configuring Layer 2 Circuit Between PE Routers


To configure Layer 2 circuit between PE1 router and PE2 router and to verify it with theshow l2circuit connections operational mode command and to ping CE routers to checkconnectivity between them:

1. On PE1 router, configure the Layer 2 circuit.

user@PE1# set protocols l2circuit neighbor 192.168.0.5 interface ge-2/1/0.600virtual-circuit-id 600 ignore-mtu-mismatch

2. On PE2 router, configure the Layer 2 circuit.

user@PE2# set protocols l2circuit neighbor 192.168.0.2 interface ge-2/1/1.600virtual-circuit-id 600 ignore-mtu-match





24/34

4. On the PE1 router, display the CE-facing Gigabit Ethernet interface information andverify that the encapsulation is configured correctly as vlan-ccc :

user@host:PE1> showinterfaces ge-2/1/0Physical interface: ge-2/1/0

Logical interface ge-2/1/0.600 (Index 196623) (SNMP ifIndex 590) Description: to-CE1 Flags: SNMP-Traps 0x4000 VLAN-Tag [ 0x8100.600 ] Encapsulation: VLAN-CCC

Input packets : 126 Output packets: 121 Protocol ccc, MTU: 1518 Flags: Is-Primary

5. On the PE1 router, display the Layer 2 circuit connections:

user@host:PE1> showl2circuit connectionsLayer-2 Circuit Connections:

Legend for connection status (St)EI -- encapsulation invalid NP -- interface h/w not presentMM -- mtu mismatch Dn -- downEM -- encapsulation mismatch VC-Dn -- Virtual circuit DownCM -- control-word mismatch Up -- operationalVM -- vlan id mismatch CF -- Call admission control failureOL -- no outgoing label IB -- TDM incompatible bitrateNC -- intf encaps not CCC/TCC TM -- TDM misconfigurationBK -- Backup Connection ST -- Standby ConnectionCB -- rcvd cell-bundle size bad SP -- Static PseudowireLD -- local site signaled down RS -- remote site standbyRD -- remote site signaled down HS -- Hot-standby ConnectionXX -- unknown

Legend for interface statusUp -- operationalDn -- downNeighbor: 192.168.0.5

Interface Type St Time last up # Up trans

ge-2/1/0.600(vc 600) rmt Up May 15 17:10:28 2013 1

Remote PE: 192.168.0.5, Negotiated control-word: Yes (Null) Incoming label: 299792, Outgoing label: 299792 Negotiated PW status TLV: No Local interface: ge-2/1/0.600, Status: Up, Encapsulation: VLAN

6. To verify that the CE routers can send and receive traffic across the Layer 2 circuits,use the ping command.

user@host:CE1> ping 172.16.1.2 count 2

PING 172.16.1.2 (172.16.1.2): 56 data bytes64 bytes from 172.16.1.2: icmp_seq=0 ttl=64 time=0.236 ms64 bytes from 172.16.1.2: icmp_seq=1 ttl=64 time=0.112 ms

--- 172.16.1.2 ping statistics ---2 packets transmitted, 2 packets received, 0% packet lossround-trip min/avg/max/stddev = 0.112/0.174/0.236/0.062 ms

user@host:CE2> ping 172.16.1.1 count 2PING 172.16.1.1 (172.16.1.1): 56 data bytes64 bytes from 172.16.1.1: icmp_seq=0 ttl=64 time=0.199 ms




25/34

64 bytes from 172.16.1.1: icmp_seq=1 ttl=64 time=0.120 ms

--- 172.16.1.1 ping statistics ---2 packets transmitted, 2 packets received, 0% packet lossround-trip min/avg/max/stddev = 0.120/0.160/0.199/0.040 ms



26/34

Results

The following displays relevant sample configuration on all the routers. Note that sincelogical systems are used in this example, the sample configuration displays are as such.

1. To display the configuration for interfaces on the router, use show interfaces :

ge-2/0/6 {vlan-tagging;unit600 {

description to-PE1;vlan-id 600;family inet {

address 172.16.1.2/24;}

}}ge-2/1/0 {

vlan-tagging;encapsulation vlan-ccc;unit600 {

description to-CE1;encapsulation vlan-ccc;vlan-id 600;family ccc;

}}ge-2/1/1 {

vlan-tagging;encapsulation vlan-ccc;unit600 {

description to-CE2;encapsulation vlan-ccc;vlan-id 600;family ccc;

}}ge-2/1/2 {

vlan-tagging;unit600 {

description to-PE2;vlan-id 600;family inet {

address 172.16.1.1/24;}

}}

2. To display the configuration on a particular logical system, run the show command:

Configuration on CE1 routerCE1 {interfaces {

ge-2/0/6 {unit 600;

}




27/34

lo0{unit 1 {

family inet {address 192.168.0.1/32;

}}}

}}

Configuration on PE1 routerPE1 {interfaces {

lt-2/0/10 {unit 5 {

description to-ASBR1;encapsulation ethernet;peer-unit 6;family inet {

address 10.0.0.5/30;}family mpls;

}}ge-2/1/0 {

unit 600;}lo0{

unit 2 {family inet {

address 192.168.0.2/32;}

}

}}protocols {

rsvp {interface lo0.2;interface lt-2/0/10.5;

}mpls {

no-cspf;label-switched-path PE1-ASBR1 {

to 192.168.0.3;ldp-tunneling;

}interface lt-2/0/10.5;

}bgp {

group int {type internal;local-address 192.168.0.2;family inet {

unicast;labeled-unicast {

rib {inet.3;



28/34

}}

}neighbor 192.168.0.3;

}}ospf {

traffic-engineering;area 0.0.0.0 {

interface lt-2/0/10.5;interface lo0.2 {

passive;}

}}ldp{

l2-smart-policy;strict-targeted-hellos;

interface lo0.2;session 192.168.0.5 {

authentication-key"$9$tt8Tu1hleWNVwSylM8Xws5QF3/t1IcvWxSrxdsYZGDikqT30ORevLO1WLNV4oDik.z6";## SECRET-DATA

}}l2circuit {

neighbor 192.168.0.5 {interface ge-2/1/0.600 {

virtual-circuit-id 600;ignore-mtu-mismatch;

}}

}}routing-options {

autonomous-system 64510;}

}Configuration on ASBR1 router

ASBR1 {interfaces {

lt-2/0/10 {unit 6 {

description to-PE1;encapsulation ethernet;peer-unit 5;


}family mpls;

}unit 9 {





29/34


}

}lo0{unit 3 {


}}

}}protocols {

rsvp {interface lo0.3;interface lt-2/0/10.6;

}

mpls {no-cspf;label-switched-path ASBR1-to-PE1 {


}interface lt-2/0/10.6;

}bgp {


unicast;

labeled-unicast {rib {

inet.3;}

}}export next-hop-self;neighbor 192.168.0.2;

}group ext {

type external;family inet {


rib {inet.3;

}}

}export send-pe;peer-as 64511;neighbor 10.0.0.10;

}}



30/34

ospf {traffic-engineering;area 0.0.0.0 {

interface lo0.3 {

passive;}interface lt-2/0/10.6;

}}ldp{

interface lo0.3;}

}policy-options {

policy-statement next-hop-self {term1 {

then {next-hop self;

}}

}policy-statement send-pe {

from {route-filter 192.168.0.2/32 exact;

}then accept;

}}routing-options {


}

Configuration on ASBR2 routerASBR2 {interfaces {

ge-2/0/9 {unit 0 {

description to-PE2;family inet {


}}lt-2/0/10 {

unit10 {



}}lo0{




31/34


address 192.168.0.4/32;}

}}}protocols {

rsvp {interface ge-2/0/9.0;interface lo0.4;

}mpls {

no-cspf;label-switched-path ASBR2-to-PE2 {


}

interface ge-2/0/9.0;}bgp {



rib {inet.3;

}}

}

export next-hop-self;neighbor 192.168.0.5;

}group ext {

type external;family inet {


rib {inet.3;

}}

}export send-pe;

peer-as 64510;neighbor 10.0.0.9;

}}ospf {

traffic-engineering;area 0.0.0.0 {

interface ge-2/0/9.0;interface lo0.4 {

passive;



32/34

}}

}ldp{

interface lo0.4;}}policy-options {

policy-statement next-hop-self {term1 {

then {next-hop self;

}}

}policy-statement send-pe {

from {route-filter 192.168.0.5/32 exact;

}then accept;

}}routing-options {


}Configuration on PE2 router

PE2 {interfaces {

ge-2/1/1 {unit 600;

}

ge-2/1/3 {unit 0 {

description to-ASBR2;family inet {


}}lo0{


address 192.168.0.5/32;}

}}

}protocols {

rsvp {interface ge-2/1/3.0;interface lo0.5;

}mpls {

no-cspf;




33/34


34/34

ge-2/1/2 {unit 600;

}lo0{

unit 6 {family inet {address 192.168.0.6/32;

}}

}}

}



• Understanding the Operation of Layer 2 Circuits Across AS Boundaries on page 2



Documents

Configuring Inter as Layer Two Circuit