Junos MPLS Fundamentals (JMF)

After successfully completing this course, students should be able to:

• Explain the reasons MPLS was originally created, and the applications offered by label-switched paths.

• Describe the structure of an MPLS label, the mechanics of the data plane, and the protocols that can advertise labels.

• Configure static LSPs, verify the routing tables they populate, and explain the label actions these LSPs perform.

• Explain the purpose and advantages of RSVP, then configure a service provider network to host RSVP LSPs.

• Configure and verify a basic RSVP label-switched path.

• Explain the purpose of the MPLS traffic engineering database, and create LSPs that use this database to calculate a path.

• Explain the purpose of RSVP bandwidth reservations, and how to configure an LSP to reserve bandwidth.

• Explain the use-cases for RSVP LSP priority levels, and configure different priority levels of a variety of LSPs.

• Explain how the Constrained Shortest-Path First algorithm can calculate traffic-engineered paths.

• Explain the messages involved in tearing down, rerouting, and maintaining LSPs and RSVP sessions.

• Describe how primary and secondary paths can be used in times of link and node failure.

• Describe the advantages of RSVP local repair paths, and how to configure the one-to-one method of local repair, otherwise known as fast reroute. • Explain the mechanics, configuration, and verification of facility backup, otherwise known as link protection and node-link protection.

• Explain how RSVP LSPs can automatically find and signal better, more optimal paths.

• Explain how LSPs can gracefully move traffic to new paths with no downtime to the user.

• Explain the mechanics by which LDP creates a full mesh of label-switched paths.

• Configure and verify a basic LDP deployment in a service provider network.

• Describe some important LDP enhancements and best practices that increase the integrity of real-world LDP deployments.

• Explain how to configure LDP to advertise labels for more than just a router's loopback.

• Explain how segment routing differs from RSVP and LDP, and configure segment routing as a replacement for LDP.

Students should have intermediate-level networking knowledge and should be familiar with the Junos OS command-line interface (CLI). Students should also attend the Introduction to the Junos Operating System (IJOS), Junos Routing Essentials (JRE), and Junos Intermediate Routing (JIR) courses prior to attending this class.

Contents Day 1

Module 1: Introduction

Module 2: MPLS—Introduction

• Describe the BGP remote next-hop mechanic, and hop-by-hop forwarding

• Explain the original historical motivations for MPLS

• List the alternative modern use cases for MPLS

Module 3: MPLS—The Mechanics

• Explain how labels are built, and how they flow between routers

• Describe the end-to-end data plane of a packet across a label-switched path

• Summarize the four primary protocols that can build label-switched paths

Module 4: MPLS—Static LSPs, and the Forwarding Plane

• Configure a service provider’s edge and core devices for MPLS

• Configure the headend router of an LSP, and explain the impact this has on the router's inet.3 table

• Configure transit routers, and verify their mpls.0 tables

o Lab 1: Static LSPs, and the Forwarding Plane

Module 5: RSVP—Introduction

• Explain the purpose, features, and advantages of RSVP

• Configure a service provider network to be ready to host RSVP label-switched paths

Module 6: RSVP—Configuring A Basic LSP

• Configure and verify an RSVP label-switched path that follows the metrically best path

• Explain the purpose of MPLS self-ping

• Explain how an RSVP LSP is signaled and created

Module 7: RSVP—The Traffic Engineering Database

• Describe the purpose of the IS-IS/OSPF traffic engineering extensions

• Configure and verify an LSP that uses the traffic engineering database to calculate its path Juniper Business Use Only

• Explain the impact that loose and strict hops can have on an LSP

o Lab 2: RSVP LSPs

Day 2

Module 8: RSVP—LSP Bandwidth Reservation

• Describe the use-cases for RSVP bandwidth reservations

• Configure LSP bandwidth reservations, and verify how these reservations are advertised

Module 9: RSVP—LSP Priorities

• Describe the problems that can be caused by RSVP LSP bandwidth reservations, and the solution offered by priority levels

• Describe the default RSVP LSP priority levels, how to configure alternative settings, and how to configure LSP soft-preemption to avoid downtime o Lab 3: RSVP—LSP Bandwidth and Priorities

Module 10: RSVP—Constrained Shortest Path First, and Admin Groups

• Describe the CSPF algorithm, along with its tie breakers

• Configure and verify admin groups on LSPs

Module 11: RSVP—LSP Failures, Errors, and Session Maintenance

• Describe the events that can tear down an LSP, and the RSVP messages that make it happen

• Describe how RSVP has changed over the years from a soft-state protocol to a reliable stateful protocol

Module 12: RSVP—Primary and Secondary Paths

• Explain the use-cases and configuration for primary and secondary paths

• Identify the benefits and trade-offs of standby secondary paths

• Show the advantage of pre-installing backup paths to the forwarding table

o Lab 4: RSVP—Primary and Secondary Paths

Module 13: RSVP—Local Repair,Part 1—One-to-One Backup, or Fast-Reroute

• Demonstrate the downtime that can be caused by a link or node failure in an MPLS network, and how a local repair path can significantly reduce this downtime

• Explain the mechanics of the one-to-one backup method

• Explain the many different meanings of the term “fast reroute”

• Configure and verify the one-to-one backup method of local repair

Module 14: RSVP—Local Repair Part 2—Facility Backup, or Node-Link-Protection

• Describe how facility backup creates local repair paths for link protection and for node protection

• Configure and verify the facility backup method

• Describe the advantages and trade-offs of the facility backup and one-to-one backup methods

o Lab 5: One-to-One Backup and Facility Backup

Day 3

Module 15: RSVP—LSP Optimization

• Describe the LSP optimization algorithm, and how to configure this feature

Module 16: RSVP—Make-Before-Break and Adaptive

• Describe the make-before-break mechanic, and list the features that use this mechanic by default

• Explain how shared explicit signaling can prevent double-counting of bandwidth, and configure this feature for all other LSPs

• Configure a policy to map specific traffic to a particular RSVP LSP

Module 17: LDP—The Label Distribution Protocol

• Describe the key features, advantages, and trade-offs of LDP

• Explain the particular methods by which LDP generates and advertises MPLS labels

Module 18: LDP—Configuration

• Configure a basic LDP deployment, and describe the protocol messages that this configuration generates

• Verify the interface messages, sessions, and labels that this configuration generates

Module 19: LDP—Enhancements and Best Practices

• Explain the LDP-IGP Synchronization feature that reduces dropped packets during topology changes

• Describe how the BGP next-hop resolution process can be altered in LDP

• Configure session protection to improve the integrity of LDP during network failure

Module 20: LDP—Egress, Import, and Export Policies

• Configure and verify LDP egress policies to advertise any FEC of your choosing

• Configure and verify LDP import and export policies to limit the distribution of FECs

o Lab 6: Label Distribution Protocol Appendix A: Segment Routing

• Explain what a segment is, and describe how segment routing advertises MPLS labels within IS-IS or OSPF

• Configure segment routing to advertise Adjacency SIDs

• Configure segment routing for shortest-path routing, as a replacement to LDP