Juniper EX9200 Features Manual page 29

Chapter 1: Understanding How GRES Enables Uninterrupted Packet Forwarding During a Routing Engine Switchover
Table 3: Effects of a Routing Engine Switchover (continued)
Feature
GRES and graceful restart enabled
Release History Table
Related
Documentation
Copyright © 2017, Juniper Networks, Inc.
Benefits
Traffic is not interrupted during the
switchover.
Interface and kernel information are
preserved.
Graceful restart protocol extensions
quickly collect and restore routing
information from the neighboring
routers.
Release Description
14.2 Starting from Junos OS Release 14.2, when you perform GRES on MX Series routers,
you must execute the
mode command on the new master Routing Engine to clear the wait-to-restore
timer on it.
12.2 Starting with Junos OS Release 12.2, if adjacencies between the restarting router
and the neighboring peer 'helper' routers time out, graceful restart protocol
extensions are unable to notify the peer 'helper' routers about the impending restart.
12.2 Starting with Junos OS Release 12.2, if adjacencies between the restarting router
and the neighboring peer 'helper' routers time out, graceful restart can stop and
cause interruptions in traffic.
Understanding High Availability Features on Juniper Networks Routers
Graceful Routing Engine Switchover System Requirements on page 11
Configuring Graceful Routing Engine Switchover on page 17
Configuring Graceful Routing Engine Switchover in a Virtual Chassis (CLI Procedure)
Configuring Graceful Routing Engine Switchover in a Virtual Chassis (CLI Procedure)
Requirements for Routers with a Backup Router Configuration on page 15
Example: Configuring IS-IS for GRES with Graceful Restart on page 20
hold-time
Considerations
Neighbors are required to support
graceful restart, and a wait interval is
required.
The routing protocol process (rpd)
restarts.
For certain protocols, a significant
change in the network can cause
graceful restart to stop.
Starting with Junos OS Release 12.2, if
adjacencies between the restarting
router and the neighboring peer
'helper' routers time out, graceful
restart can stop and cause
interruptions in traffic.
clear synchronous-ethernet wait-to-restore
operational
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