# Referencing Policies in Service Definitions

In Profile Configuration mode, policy interface commands for IP and L2TP allow attachments to be merged into any existing merge-capable attachment at an attachment point. Merged policies are dynamically created. Service Manager can request that multiple interface profiles be applied or removed at an interface as part of service activation or deactivation. Service Manager also specifies whether or not the attachments created from these interface profiles persist on subsequent reloads.

Service Manager can specify whether a component policy attachment is non-volatile. If the interface where the component policy is attached is volatile, then policy management makes the attachment volatile even when the Service Manager specifies otherwise. A non-volatile interface can have both volatile and non-volatile component policy attachments. The merged policy that is created is the merge of all component policies attached at a given attachment point regardless of their volatility. The merged policy and its attachments are always volatile and reconstructed on each reload operation.

For further details on merging policies, see the Merging Policies chapter inJunosE Policy Management Configuration Guide.