Juniper TX MATRIX Hardware Manual page 280

TX Matrix Hardware Guide
Table 30: Effect of Taking the Host Subsystem Offline (continued)
Master host subsystem
248
The backup host subsystem becomes the master. The backup Routing Engine assumes Routing
Engine functions. The master host subsystem is hot-pluggable.
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 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.
To take a host subsystem offline:
Determine whether the host subsystem is functioning as the master or as the backup,
1.
using one of the two following methods:
Check the Routing Engine LEDs on the craft interface. If the green
lit, the corresponding host subsystem is functioning as the master.
Issue the following CLI command. The master Routing Engine is designated
in the field:
Current state
user@host> show chassis routing-engine scc
Routing Engine status:
Slot 0:
Current state
...
If the host subsystem is functioning as the master, switch it to backup using the CLI
2.
command:
user@host> request chassis routing-engine master switch scc
If the Routing Engines are running the same Junos OS release and are configured for
nonstop active routing, the standby Routing Engine immediately assumes Routing
Engine functions and there is no interruption to packet forwarding. Otherwise, packet
forwarding halts while the standby Routing Engine becomes the master and the Packet
Forwarding Engine components reset and connect to the new master Routing Engine.
For information about configuring graceful switchover, see the Junos OS High Availability
Configuration Guide.
MASTER
Master
Copyright © 2010, Juniper Networks, Inc.
LED is
Master