Multiple bypass LSPs can satisfy a backup path request to a MP. When both static bypass LSPs and dynamic bypass LSPs are available to an MP, the statically created bypass LSPs are preferred over the dynamically created bypass LSPs.
When there are multiple bypass LSPs of the same type, selection among them is based on the bypass LSP path cost and the number of backups currently associated with the bypass LSP. The first level of selection is based on the bypass LSP path cost. When there are multiple equal-cost bypass LSPs, then the bypass LSP with least number of riding backup paths is chosen.
By default, while selecting a bypass LSP for backup, the cost of a bypass LSP is considered as zero (0). In such a scenario, only the number of riding backups is used for selecting between equal zero-cost bypass LSPs.
Both the cost and the number of riding backups are considered when selecting a bypass LSP using the cspf-computation-mode use-bypass-metric command in the MPLS router policy configuration mode.