ERO Exclude Option
In order to allow more flexibility when traffic engineering redundant paths for RSVP-TE LSPs, this feature adds the “exclude” option to the “configure mpls rsvp-te path <path> add ero” command. An “include” option is also available, but is optional. If neither option is used, “include” will be used for backward compatibility.
A hop that is excluded is avoided when CSPF does path calculations. By adding an “exclude” hop to a path, LSPs can be set up to avoid certain links. An example of this is to configure a secondary RSVP-TE LSP to avoid the hops that a primary LSP has been configured to traverse. This can allow the secondary LSP more freedom to route through other parts of the network. Often, without the “exclude” option, the secondary LSP must be configured more tightly than desired to ensure that its path never overlaps with the primary LSP‘s path.