Path Selection for CSPF Computation

The selection of path for the LSP depends on whether you want to use IGP or TE metric for CSPF computation. Consider the network topology in the illustration. The ingress router is DUT 1 and the egress router is DUT 5. There are two cases depending upon whether IGP metric or TE metric is used for CSPF computation.

When IGP metric is selected

The LSP selects the following path:

• DUT1 --> DUT2 --> DUT4 --> DUT5

When TE metric is selected

The LSP selects the following path:

• DUT1 --> DUT4 --> DUT3 --> DUT5