This selects which fast-reroute protection method the device uses, and the description warns that some devices may require a routing-processor reboot to change it, with an agent unwilling to reboot or change modes returning an inconsistentValue error. Switching this value toggles the router between per-LSP detour tunnels (oneToOneBackup, one dedicated backup LSP per protected path) and shared bypass tunnels (facilityBackup, many LSPs sharing fewer backup tunnels), so admins should expect a SET here to possibly be rejected or to disrupt existing sessions rather than take effect instantly. For example, an admin migrating a busy PLR from oneToOneBackup to facilityBackup to collapse hundreds of individual detour LSPs down to a handful of shared bypass tunnels may need to schedule a maintenance window if the platform enforces a reboot on this change.