Graceful Routing Engine Switchover System Requirements

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

Graceful Routing Engine Switchover Platform Support

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

M20 and M40e routers—Junos OS Release 5.7 or later
M10i router—Junos OS Release 6.1 or later
M320 router—Junos OS Release 6.2 or later
T320 router, T640 router, and TX Matrix router—Junos OS Release 7.0 or later
M120 router—Junos OS Release 8.2 or later
MX960 router—Junos OS Release 8.3 or later
MX480 router—Junos OS Release 8.4 or later (8.4R2 recommended)
MX240 router—Junos OS Release 9.0 or later
PTX5000 router—Junos OS Release 12.1X48 or later
Standalone T1600 router—Junos OS Release 8.5 or later
Standalone T4000 router—Junos OS Release 12.1R2 or later
TX Matrix Plus router—Junos OS Release 9.6 or later
TX Matrix Plus router with 3D SIBs—Junos Release 13.1 or later
EX Series switches with dual Routing Engines or in a Virtual Chassis — Junos OS Release 9.2 or later for EX Series switches
QFX Series switches in a Virtual Chassis —Junos OS Release 13.2 or later for the QFX Series
EX Series or QFX Series switches in a Virtual Chassis Fabric —Junos OS Release 13.2X51-D20 or later for the EX Series and QFX Series switches

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 OS features in Release 5.7 and later. Particular Junos OS features require specific versions of Junos OS. See Table 4.

Table 4: Graceful Routing Engine Switchover Feature Support

Application	Junos OS Release
Aggregated Ethernet interfaces with Link Aggregation Control Protocol (LACP) and aggregated SONET interfaces	6.2
Asynchronous Transfer Mode (ATM) virtual circuits (VCs)	6.2
Logical systems Note: In Junos OS Release 9.3 and later, the logical router feature is renamed to logical system.	6.3
Multicast	6.4 (7.0 for TX Matrix router)
Multilink Point-to-Point Protocol (MLPPP) and Multilink Frame Relay (MLFR)	7.0
Automatic Protection Switching (APS)—The current active interface (either the designated working or the designated protect interface) remains the active interface during a Routing Engine switchover.	7.4
Point-to-multipoint Multiprotocol Label Switching MPLS LSPs (transit only)	7.4
Compressed Real-Time Transport Protocol (CRTP)	7.6
Virtual private LAN service (VPLS)	8.2
Ethernet Operation, Administration, and Management (OAM) as defined by IEEE 802.3ah	8.5
Extended DHCP relay agent	8.5
Ethernet OAM as defined by IEEE 802.1ag	9.0
Packet Gateway Control Protocol (PGCP) process (pgcpd) on Multiservices 500 PICs on T640 routers.	9.0
Subscriber access	9.4
Layer 2 Circuit and LDP-based VPLS pseudowire redundant configuration	9.6

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. However, note that this restriction does not apply to MX Series Routers that are running Junos OS Release 9.4 or later and have distributed periodic packet management (PPM) enabled—which is the default configuration—on them. In such cases, you can configure graceful Routing Engine switchover and have aggregated Ethernet interfaces configured for fast-polling LACP on the same device.
VRRP changes mastership when a Routing Engine switchover occurs, even when graceful Routing Engine switchover is configured.

Graceful Routing Engine Switchover DPC Support

Graceful Routing Engine switchover supports all Dense Port Concentrators (DPCs) on the MX Series 3D Universal Edge Routers running the appropriate version of Junos OS as shown in Graceful Routing Engine Switchover Platform Support. 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 and dynamic PPPoE subscriber access. Graceful Routing Engine switchover also supports the unified in-service software upgrade (ISSU) for the DHCP access model and the PPPoE access model used by subscriber access.

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 OS. For information about FPC types, FPC/PIC compatibility, and the initial Junos OS 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—except the Layer 2 service packages and extension-provider and SDK applications on Multiservices 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.