Configuring AS or MultiServices PIC Redundancy

You can configure AS or MultiServices PIC redundancy on M-series and T-series routing platforms, except TX Matrix platforms, that have multiple AS or MultiServices PICs. To configure redundancy, you specify a redundancy services PIC (rsp) interface in which the primary PIC is active and a secondary PIC is on standby. If the primary PIC fails, the secondary PIC becomes active, and all service processing is transferred to it. If the primary AS or MultiServices PIC is restored, it remains on standby and does not preempt the secondary PIC; you need to manually restore the services to the primary PIC. To determine which PIC is currently active, issue the show interfaces redundancy command.

Failover to the secondary PIC occurs under the following conditions:

• The primary PIC, FPC, or Packet Forwarding Engine goes down, resets, or is physically removed from the router.
• The PIC or FPC is taken offline using the request chassis pic fpc-slot slot-number pic-slot slot-number offline or request chassis fpc slot slot-number offline command. For more information, see the JUNOS System Basics and Services Command Reference.
• The driver watchdog timer expires.
• The request interface switchover command is issued. For more information, see the JUNOS Interfaces Command Reference.

Note: Adaptive Services and MultiServices PICs in Layer-2 mode (running Layer 2 services) are not rebooted when a MAC flow-control situation is detected.

The physical interface type rsp specifies the pairings between primary and secondary sp interfaces to enable redundancy. To configure an AS or MultiServices PIC as the backup, include the redundancy-options statement at the [edit interfaces rspnumber] hierarchy level:

Note: You can include a similar redundancy configuration for Link Services IQ (LSQ) PICs at the [edit interfaces rlsqnumber] hierarchy level. For more information, see Configuring LSQ Interface Redundancy in a Single Router Using Virtual Interfaces.

The following constraints apply to redundant AS or MultiServices PIC configurations:

• The services supported in redundancy configurations include stateful firewall, NAT, IDS, and IPsec. Services mounted on the AS or MultiServices PIC that use interface types other than sp- interfaces, such as tunneling and voice services, are not supported. For information on flow monitoring redundancy, see Configuring Services Interface Redundancy with Flow Monitoring.

  Note: For IPsec functionality, the router no longer needs to renegotiate security associations (SAs) during warm standby PIC switchover. Instead, the warm standby feature has been made stateful by periodically setting a checkpoint between the working state of the PIC and the Routing Engine, which should lessen the downtime during switchover. If you prefer to retain the earlier behavior, you can include the clear-ipsec-sas-on-pic-restart statement at the [edit services ipsec-vpn] hierarchy level. If you enable this capability, the router renegotiates the IPsec SAs on warm standby PIC switchover. For more information, see Clearing Security Associations.

• We recommend that you pair the same model type in RSP configurations, such as two ASMs or two AS2 PICs. If you pair unlike models, the two PICs may perform differently.
• You can specify an AS or MultiServices PIC (sp interface) as the primary for only one rsp interface.
• An sp interface can be a secondary for multiple rsp interfaces. However, the same sp interface cannot be configured as a primary interface in one rsp configuration and as a secondary in another configuration.
• When the secondary PIC is active, if another primary PIC that is paired with it in an rsp configuration fails, no failover takes place.
• When you configure an AS or MultiServices PIC within a redundant configuration, the sp interface cannot have any configured services. Apply the configurations at the [edit interfaces rspnumber] hierarchy level, using, for example, the unit and services-options statements. Exceptions include the multiservice-options statement used in flow monitoring configurations, which can be configured separately for the primary and secondary sp interfaces, and the traceoptions statement.
• All the operational mode commands that apply to sp interfaces also apply to rsp interfaces. You can issue show commands for the rsp interface or the primary and secondary sp interfaces.
• If a secondary PIC fails while it is in use, the rsp interface returns to the “ not present” state. If the primary PIC comes up later, service is restored to it.

For a sample configuration, see Examples: Configuring Services Interfaces.