Advertising MPLS labels in IGPs - PowerPoint PPT Presentation

Advertising MPLS labels in IGPs draft-gredler-rtgwg-igp-label-advertisement IETF86 Hannes Gredler March 2013 <hannes@juniper.net>

Motivation and Rationale • R-LFA implementation requires IS-IS LDP more tight integration of LDP and LFA rt-backup rt IGP IGP Base IGP Topo rt-flash mpls.0 LDP IGP Base N1 rslv Base • Bi-directional notification IGP Topo Base Base Topo rt N2 context Topo rt inet.0 path between protocols N3 • MPLS transport label distribution inet.3 rt-flash are Session oriented protocols • You need to have a sessio n with a neighbor in order to receive/distribute bindings • Interesting use cases for >1 hop distribution of transport labels

USE CASE #1 INCREASE (R-)LFA COVERAGE

Pathologic Topologies D H M4 >= M1+M2+M3 Primary forwarding M1 M3 path PLR E M2 looped backup traffic

Add one-hop strict forwarding labels (stack ‘em) Explicit 1-hop tunnel IGP advertisement: Neighbor D: label 100 Neighbor E: label 200 D H M4 >= M1+M2+M3 Primary forwarding M1 M3 path PLR E M2 Backup tunnel to helper

USE CASE #2 TE BY LABEL-STACKING

TE by label stacking per-neighbor labels IGP advertisement: IGP advertisement: Neighbor S: label 100 Neighbor R1: label 201 Neighbor R2: label 102 Neighbor D: label 205 Neighbor R4: label 104 Neighbor R4: label 204 2 R2 R1 2 2 5 5 S D 1 1 1 R3 R4 IGP advertisement: Neighbor R1: label 401 Neighbor R2: label 402 Neighbor R4: label 404 Neighbor D: label 405

USE CASE #3 ADVERTISING TE LSPS

Advertise RSVP LSPs as Forwarding Adjacency Issue: LSP path properties lost 2 2 R2 R1 R5 2 2 S D 5 5 5 RSVP Tunnel 1 1 IGP FA R3 R4 R6 1 1

Advertise existing LSPs & EROs -> Allows path property correlation 2 2 R2 R1 R5 2 2 S D 5 5 5 RSVP Tunnel 1 1 R3 R4 R6 1 1 IGP advertisement: Neighbor R1: label 401, ERO (R1) Neighbor R2: label 402, ERO (R2) Neighbor R3: label 403, ERO (R3) Neighbor R6: label 406, ERO (R6) Neighbor R6: label 407, ERO (R2, R6)

USE CASE #4 EGRESS WAN SDN CONTROL(ER)

Current TE framework only offers egress Node control. -> No good Egress Link control tweak BGP import policy AS 2 91/8 AS1 ASBR3 R1 ASBR1 91/8 ASBR4 S AS 3 91/8 ASBR5 R2 ASBR2 91/8 ASBR6

SDN ECMP weight controller and per-neighbor label AS 2 91/8 AS1 ASBR3 ASBR1 R1 91/8 ASBR4 S Traffic stats AS 3 91/8 ASBR5 ECMP weigths R2 ASBR2 Traffic stats 91/8 ASBR6 SDN controller

Next ¡Steps ¡ • Yesterday ¡(20130313) ¡submission ¡isis-­‑wg ¡ – dra=-­‑previdi-­‑filsfils-­‑isis-­‑segment-­‑rouAng-­‑00 ¡ – Core ¡is ¡adverAsing ¡“segments” ¡for ¡source ¡rouAng ¡ – IGP ¡disseminates ¡“segment” ¡ – Some ¡similariAes ¡(IGP ¡label) ¡ – Some ¡discrepancies ¡(AdverAsing ¡exisAng ¡labels, ¡ Gloab ¡labels) ¡ – Working ¡with ¡authors ¡to ¡assess ¡dra= ¡merge ¡