Multiple Bypass LSPs

By default, link protection relies on a single bypass LSP to provide path protection for an interface. However, you can also specify multiple bypass LSPs to provide link protection for an interface. You can individually configure each of these bypass LSPs or create a single configuration for all of the bypass LSPs. If you do not configure the bypass LSPs individually, they all share the same path and bandwidth constraints.

The following algorithm describes how and when an additional bypass LSP is activated for an LSP:

1. If any currently active bypass can satisfy the requirements of the LSP (bandwidth, link protection, or node-link protection), the traffic is directed to that bypass.
2. If no active bypass LSP is available, scan through the manual bypass LSPs in first-in, first-out (FIFO) order, skipping those that are already active (each manual bypass can only be activated once). The first inactive manual bypass that can satisfy the requirements is activated and traffic is directed to that bypass.
3. If no manual bypass LSPs are available and if the max-bypasses statement activates multiple bypass LSPs for link protection, determine whether an automatically configured bypass LSP can satisfy the requirements. If an automatically configured bypass LSP is available and if the total number of active automatically configured bypass LSPs does not exceed the maximum bypass LSP limit (configured with the max-bypasses statement), activate another bypass LSP.

For information on how to configure multiple bypass LSPs for link protection, see Configuring Bypass LSPs.

Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice.