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TX Matrix Plus Component Redundancy

 

A routing matrix with a TX Matrix Plus router is designed so that no single point of failure can cause the entire system to fail. For more information about high availability features, see the Junos OS High Availability Library for Routing Devices.

The following major hardware components are redundant:

Cooling System Redundancy

The cooling system has redundant components, which are controlled by the host subsystem. If one of the fans fails, the host subsystem increases the speed of the remaining fans to provide sufficient cooling for the TX Matrix Plus router indefinitely.

Power Supply Redundancy

The TX Matrix Plus router has two power supplies, which share the load evenly. If one power supply fails, the other power supply can provide full power to the TX Matrix Plus router indefinitely.

Connector Interface Panel Redundancy

The TX Matrix Plus router has two TXP-CIPs. Each TXP-CIP provides the ports for the control plane connections to the Control Boards (LCC-CBs) to the line-card chassis (LCCs) .

If the master TXP-CIP fails, the backup TXP-CIP provides redundant connections to the active host subsystem in the TX Matrix Plus router and the active LCC-CBs in the LCCs. In this case, the Routing Engines in the TX Matrix Plus router and the LCCs do not perform a switchover to their backups.

Switching Plane Redundancy

See Switching Plane Redundancy for a Routing Matrix with a TX Matrix Plus Router for more information.

Host Subsystem (Control Board and Routing Engine) Redundancy

Host subsystem—The host subsystem consists of a Routing Engine functioning together with a TXP-CB. The TX Matrix Plus router can have one or two host subsystems. To operate, each host subsystem requires a Routing Engine installed directly into the TXP-CB. If two host subsystems are installed, one functions as the master and the other functions as the backup.

If the master host subsystem (or either of its components) fails, the backup can take over as the master.

Table 1 shows the effect of taking a master, backup, and nonredundant host subsystem offline.

Table 1: Effect of Taking the Host Subsystem Offline

Type of Host Subsystem

Effect of Taking the Host Subsystem Offline

Nonredundant host subsystem

The TX Matrix Plus router shuts down.

Backup host subsystem

The functioning of the TX Matrix Plus router is not interrupted. The backup host subsystem is hot-removable and hot-insertable.

Master host subsystem

The backup host subsystem becomes the master. The backup Routing Engine assumes Routing Engine functions. The master host subsystem is hot-pluggable.

Nonstop active routing is supported in the following Junos OS releases:

  • TXP-T1600 configuration—The TX Matrix Plus router and connected T1600 LCC support NSR in Junos OS Release 10.0 and later.

  • TXP-T1600-3D configuration—The TX Matrix Plus router and connected T1600 LCC support NSR in Junos OS Release 13.1 and later.

  • TXP-T4000-3D configuration—The TX Matrix Plus router and connected T4000 LCC support NSR in Junos OS Release 13.1 and later.

  • TXP-Mixed-LCC-3D configuration—The TX Matrix Plus router and connected LCC support NSR in Junos OS Release 13.1 and later.

During the switchover:

  • Graceful Routing Engine switchover (GRES) and nonstop active routing (NSR) are both configured—Packet forwarding and routing are continued without interruption.

  • GRES is configured but NSR is not configured—Packet forwarding continues but routing is interrupted momentarily.

  • GRES and NSR are not configured—Packet forwarding halts while the standby Routing Engine becomes the master. The Packet Forwarding Engine components reset and connect to the new master Routing Engine.

Note: TX Matrix Plus router performance might change if the backup Routing Engine's configuration differs from the former master's configuration. For the most predictable performance, configure the two Routing Engines identically, except for parameters unique to each Routing Engine.

For information about configuring graceful switchover and nonstop active routing, see the Junos OS High Availability Library for Routing Devices.

We recommend that you run the same Junos OS release on the master and backup Routing Engines. If you choose to run different Junos OS releases on the Routing Engines, a change in Routing Engine mastership can cause one or all LCCs to be logically disconnected from the TX Matrix Plus router.

Table 2: Effect of Switching a TX Matrix Plus or LCC Routing Engine

Configuration

Effect of a Change in Mastership

The on-loss-of-keepalives statement is included at the [edit chassis redundancy failure] hierarchy level

You or a host subsystem initiates a change in mastership to the backup Routing Engine in the TX Matrix Plus router—The master Routing Engines in the LCCs detect a software release mismatch with the new master Routing Engine in the TX Matrix Plus router and switch mastership to their backup Routing Engines.

You attempt to initiate a change in mastership to a backup Routing Engine in an LCC—The new master Routing Engine in the LCCdetects a software release mismatch with the master Routing Engine in the TX Matrix Plus router and relinquishes mastership to the original master Routing Engine. Routing Engine mastership in the TX Matrix Plus router does not switch in this case.

A host subsystem initiates a change in mastership to a backup Routing Engine in an LCC because the master Routing Engine has failed—The LCC is logically disconnected from the TX Matrix Plus router.

The on-loss-of-keepalives statement is not included at the [edit chassis redundancy failure] hierarchy level

You initiate a change in mastership to the backup Routing Engine in the TX Matrix Plus router—All LCCs are logically disconnected from the TX Matrix Plus router.

You initiate a change in mastership to a backup Routing Engine in an LCC—The LCC is logically disconnected from the TX Matrix Plus router. To reconnect the LCC, switch mastership of the new master Routing Engine in the LCC back to the original master Routing Engine.