Juniper QFX3000-G QFabric, Deployment Manual, Page: 46 / 652

Routing Engines perform many important processing tasks in the QFabric system. Knowing
where the Routing Engines are located and what services they provide enables you to
troubleshoot the QFabric system and ensure that it is running the way it should.
This topic covers:
•
Hardware-Based Routing Engines on page 20
• Software-Based External Routing Engines on page 20
Hardware-Based Routing Engines
A traditional Juniper Networks Routing Engine is a hardware field-replaceable unit that
runs routing protocols, builds the routing and switching tables, sends routing information
to the Packet Forwarding Engine, and handles several software processes for the device
(such as interface control, chassis component monitoring, system management, and
user access). Node devices that are part of server Node groups in the QFabric system
that connect to servers or storage devices implement Routing Engine functions locally
using this traditional hardware method.
Software-Based External Routing Engines
The QFabric system also uses external Routing Engines that run in software on the Director
group. In contrast with traditional Routing Engines, the functions and processes provided
by software-based Routing Engines are segmented, specialized, and distributed across
multiple Routing Engine instances running on the Director group. Such separation provides
redundancy for these functions and enables the QFabric system to scale.
Figure 4 on page 20 shows the external Routing Engine types.
Figure 4: External Routing Engine Types
Fabric control
Fabric manager
Network Node group
Fabric visualizer
Diagnostics
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These special-purpose external Routing Engine instances running on the Director group
provide the following major services for the QFabric system:
•
Fabric manager Routing Engine —Provides services to all devices in the QFabric system,
such as system initialization, topology discovery, internal IP address and ID assignment,
and interdevice communication. The fabric manager Routing Engine authenticates
Interconnect and Node devices, and maintains a database for system components. A
single fabric manager Routing Engine instance is generated to manage the entire
QFabric system.
• Fabric control Routing Engine —Runs the fabric control protocol to share route
information between available devices in a partition. A pair of redundant route
Copyright © 2015, Juniper Networks, Inc. 20
QFX3000-G QFabric System Deployment Guide