Graceful Routing Engine Switchover System Requirements

Graceful Routing Engine switchover is supported on all routing platforms that contain dual Routing Engines. All Routing Engines configured for graceful Routing Engine switchover must run the same JUNOS software release. Hardware and software support for graceful Routing Engine switchover is described in the following sections:

• Graceful Routing Engine Switchover Platform Support
• Graceful Routing Engine Switchover Feature Support
• Graceful Routing Engine Switchover DPC Support
• Graceful Routing Engine Switchover and Subscriber Access
• Graceful Routing Engine Switchover PIC Support

Graceful Routing Engine Switchover Platform Support

To enable graceful Routing Engine switchover, your system must meet these minimum requirements:

• M20 and M40e routers—JUNOS Release 5.7 or later
• M10i router—JUNOS Release 6.1 or later
• M320 router—JUNOS Release 6.2 or later
• T320 router, T640 routing node, and TX Matrix platform—JUNOS Release 7.0 or later
• M120 router—JUNOS Release 8.2 or later
• MX960 Ethernet Services router—JUNOS Release 8.3 or later
• MX480 Ethernet Services router—JUNOS Release 8.4 or later (8.4R2 recommended)
• MX240 Ethernet Services router—JUNOS Release 9.0 or later
• T1600 routing node—JUNOS Release 8.5 or later

For more information about support for graceful Routing Engine switchover, see the sections that follow.

Graceful Routing Engine Switchover Feature Support

Graceful Routing Engine switchover supports most JUNOS software features in Release 5.7 and later. Particular JUNOS software features require specific versions of the JUNOS software. See Table 7.

Table 7: Graceful Routing Engine Switchover Feature Support

The following constraints apply to graceful Routing Engine switchover feature support:

• When graceful Routing Engine switchover and aggregated Ethernet interfaces are configured in the same system, the aggregated Ethernet interfaces must not be configured for fast-polling LACP. When fast polling is configured, the LACP polls time out at the remote end during the Routing Engine mastership switchover. When LACP polling times out, the aggregated link and interface are disabled. The Routing Engine mastership change is fast enough that standard and slow LACP polling do not time out during the procedure.
• VRRP changes mastership when a Routing Engine switchover occurs, even when graceful Routing Engine switchover is configured.
• The extended DHCP local server does not support graceful Routing Engine switchover. Address-assignment pools do not support graceful Routing Engine switchover. For more information, see the JUNOS System Basics Configuration Guide.

Graceful Routing Engine Switchover DPC Support

Graceful Routing Engine switchover supports all Dense Port Concentrators (DPCs) on the MX-series routing platform running the appropriate version of JUNOS software. For more information about DPCs, see the MX-series DPC Guide.

Graceful Routing Engine Switchover and Subscriber Access

Graceful Routing Engine switchover currently supports most of the features directly associated with dynamic DHCP subscriber access. However, Graceful Routing Engine switchover does not support unified in-service software upgrade (ISSU) on systems that are running DHCP subscriber access. In addition, any partially complete subscriber secure policy activations that are lost during a failure are not recovered.

Graceful Routing Engine Switchover PIC Support

Graceful Routing Engine switchover is supported on most PICs, except for the services PICs listed in this section. The PIC must be on a supported routing platform running the appropriate version of JUNOS software. For information about FPC types, FPC/PIC compatibility, and the initial JUNOS software release in which an FPC supported a particular PIC, see the PIC guide for your router platform.

The following constraints apply to graceful Routing Engine switchover support for services PICs:

• You can include the graceful-switchover statement at the [edit chassis redundancy] hierarchy level on a router with Adaptive Services, MultiServices, and Tunnel Services PICs configured on it and successfully commit the configuration. However, all services on these PICs are reset during a switchover.
• Graceful Routing Engine switchover is not supported on any Monitoring Services PICs or Multilink Services PICs. If you include the graceful-switchover statement at the [edit chassis redundancy] hierarchy level on a router with either of these PIC types configured on it and issue the commit command, the commit fails.
• Graceful Routing Engine switchover is not supported on Multiservices 400 PICs configured for monitoring services applications. If you include the graceful-switchover statement, the commit fails.

Note: When an unsupported PIC is online, you cannot enable graceful Routing Engine switchover. If graceful Routing Engine switchover is already enabled, an unsupported PIC cannot come online.