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Example R1 in Area A requests a path setup (and record route) to node R6 in Area C. first path traverses (R1,R2,ABR1,Rx, ABR3,R4,R6) R1 requests a second path setup to R6, specifying SRLG (derive from route recorded in first step) to exclude e.g. exclude (R2,SRLGA, ABR1,SRLGB, Rx,ABR3,SRLGC,R4) second path traverses (R1,R3,ABR2,Ry,ABR4,R5,R6) Note: This approach of setting up alternate paths may be less optimal then the route server approach in http://www.ietf.org/proceedings/00dec/slides/TEWG-6/sld010.htm (draft-lee-mpls-path-request-03.txt), but requires less implementation work, offloads route servers, and may be “good enough” R1 ABR1 ABR2 ABR3 ABR4 R6 R2 R3 R4 R5 Area A Area B Area C Rx Ry