This indicates whether auto-backup (automatic creation of a backup LSP for this tunnel without manual configuration of the backup) is enabled, and per the description always reads 0 when this row itself represents a backup tunnel rather than a primary. An admin checks this specifically on primary tunnels to confirm the device is automatically maintaining a standby path, and knows to interpret a value of 0 on a backup-role row as expected rather than a misconfiguration. For example, seeing this enabled (1) on a primary tunnel confirms the device is auto-provisioning its own backup, while a 0 on the paired backup row for that same tunnel is normal, not an error.