MPLS Protection and Restoration – Part 5 (Fast Reroute Protection Types)

mpls-point-of-local-repair-(PLR)-and-merge-point-(MP)

Both One-to-One and Facility Backup can protect different network elements. And these can be achieved by two ways:

– Node Protection : Protect against the failure of the next downstream router. The upstream router before the failure node establishes a protection tunnel that goes around the failed next downstream router. This is default behaviour.

– Link Protection : Protect against the failure of the link to the next downstream router. The upstream router before the failure link establishes a protection tunnel that goes around the failed link to the next downstream router.

Let’s talk about this protection types detailly.

Link Protection

Link protection is protecting the link along an LSP. For this protection process, a backup link is created. As we say before the protection process also classified into two as one-to-one backup and facility backup.

If the backup link is created for One-to-one (Fast Reroute) Backup, it is called “detour”.
If it is created for Many-to-one (Facility) Backup, then it is called “bypass”.

mpls point of local repair (PLR) and merge point(MP),MPLS Recovery
 

Fast Reroute Link Protection,MPLS Recovery

Node Protection

Node protection is the protection type with which we can provide protection for both link and node failures.

In node protection the terms Point of Local Repair (PLR) and MP(Merge Point) is used again. Here, the MP point is the downstream router of the protected node. This backup type is called “next-next-hop backup”.

mpls node protection next-next-hop backup,MPLS Recovery
 

Fast Reroute Node Protection, Next-Next-Hop Backup

For this protection type, the PLR router need to know some information about MP router.
These informations are:

The address of the MP router ( This information can be obtained from Record Route Object,RRO),
The label value used by the protected LSP ( To provide this information, the “label recording desired” must be defined in the Session Attribute Object. By setting this, label information is included in RRO)

Here I would like to take your attantion to the one point. Maybe you can compare end-to-end protection and local protection(fast reroute) and decide that end-to-end is not necessary. Because fast reroute have more specific control on traffic. But this is not completely true. Yes, with fast reroute you can have exact control on the traffic but beside fast reroute, secondary paths also need to be used for fast recovery. So end-to-end protection ‘s secondary path and fast reroute used complementary.

The default protection type is Node Protection. Every router on the LSP tries for Node Protection 3 times. If they fail, then turns to attemp for Link Protection. After three Link Protection attemp, if they fails, then turns Node Protection again. This default behaviour can be change for only Link Protection Attemp.

You can check the other parts of these MPLS Protection and Restoration Article series below.

MPLS Protection and Restoration – Part 1
MPLS Protection and Restoration – Part 2 (End-to-End Protection, Secondary Paths)
MPLS Protection and Restoration – Part 3 (Path Diversity in Secondary Paths)
MPLS Protection and Restoration – Part 4 (Local Protection, Fast Reroute)
MPLS Protection and Restoration – Part 5 (Fast Reroute Protection Types)
MPLS Protection and Restoration – Part 6 (RSVP Objects Used for MPLS Fast Reroute)
MPLS Protection and Restoration – Part 7 (Verification Commands on Alcatel-Lucent Routers)
MPLS Protection and Restoration – Part 8 (Actions After the Failure)
MPLS Protection and Restoration – Part 9 (Convergence Factors)
MPLS Protection and Restoration – Part 10 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 11 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 12 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 13 (Juniper Configuration Samples)

…YOU CAN REACH ALL THE “MPLS” ARTICLES AND CONFIGURATIONS BELOW…

MPLS Basics

What is MPLS?
Enabling MPLS on Cisco Router

MPLS Label Distribution Protocol, LDP

MPLS Label Distribution Protocol, LDP – Part 1
MPLS Label Distribution Protocol, LDP – Part 2
MPLS Label Distribution Protocol, LDP – Part 3 (Configuration on ALU)
MPLS Label Distribution Protocol, LDP – Part 4 (ECMP)
MPLS Label Distribution Protocol, LDP – Part 5 (Export and Import Policy, Prefix Aggregation)
MPLS Label Distribution Protocol, LDP – Part 6 (T-LDP)
MPLS Label Distribution Protocol, LDP – Part 7 (CR-LDP)

MPLS, RSVP-TE

MPLS, RSVP-TE – Part 1
MPLS, RSVP-TE – Part 2(Alcatel-Lucent Configuration)

MPLS Protection And Restoration

MPLS Protection and Restoration – Part 1
MPLS Protection and Restoration – Part 2 (End-to-End Protection, Secondary Paths)
MPLS Protection and Restoration – Part 3 (Path Diversity in Secondary Paths)
MPLS Protection and Restoration – Part 4 (Local Protection, Fast Reroute)
MPLS Protection and Restoration – Part 5 (Fast Reroute Protection Types)
MPLS Protection and Restoration – Part 6 (RSVP Objects Used for MPLS Fast Reroute)
MPLS Protection and Restoration – Part 7 (Verification Commands on Alcatel-Lucent Routers)
MPLS Protection and Restoration – Part 8 (Actions After the Failure)
MPLS Protection and Restoration – Part 9 (Convergence Factors)
MPLS Protection and Restoration – Part 10 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 11 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 12 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 13 (Juniper Configuration Samples)

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