Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Guide That Contains This Content
[+] Expand All
[-] Collapse All

    Understanding the Effect of Taking the Host Subsystem Offline

    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.

    Note: The TX Matrix Plus router and any connected T1600 routers support nonstop active routing in Junos OS Release 10.0 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 Configuration Guide PDF Document.

    Published: 2011-12-19