Hi Everyone, When multiple (i.e., two or more) failures on the current flooding topology (FT for short) happen at almost the same time, the FT may be split even though the real network topology is connected. A solution or procedure for fixing the FT split is described below. It uses almost the minimum number of links, and is triggered by the multiple failures. When the multiple failures on the FT occur, a backup path for each of the failures is computed, wherein the links on the backup path are not on the FT. The links on the backup path are temporarily added to the FT (i.e., the temporary flooding is enabled on the links on the backup path). Thus the split FT is connected by the backup paths. When any node N detects the multiple failures on the FT, it computes a backup path for each of the failures. If it (i.e., node N) is on the backup path, it adds its local links (e.g., local link L1 and L2) on the backup path to the FT temporarily; otherwise, it does not do anything. For a failure on the FT, the backup path computed by any node N needs to be the same. Suppose that the two end nodes of a failed link L on the FT is A and B, and A's ID is smaller than B's. Node N computes a path from A to B with minimum hops and whose links are not on the FT. This path is a backup path for link L. When every node on the backup path computes a backup path in this way in parallel, the same backup path is obtained, and used to fix the FT split.
Best Regards, Huaimo
_______________________________________________ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
