Figure 1: Preparing For A Graceful Routing Engine Switchover - Juniper EX9200 Features Manual

High Availability Feature Guide for EX9200 Switches
6
Figure 1 on page 6 shows the system architecture of graceful Routing Engine switchover
and the process a routing platform follows to prepare for a switchover.

Figure 1: Preparing for a Graceful Routing Engine Switchover

NOTE: Check GRES readiness by executing both:
The request chassis routing-engine master switch check
master Routing Engine
The
show system switchover
The switchover preparation process for GRES is as follows:
The master Routing Engine starts.
1.
The routing platform processes (such as the chassis process [chassisd]) start.
2.
The Packet Forwarding Engine starts and connects to the master Routing Engine.
3.
All state information is updated in the system.
4.
The backup Routing Engine starts.
5.
The system determines whether GRES has been enabled.
6.
The kernel synchronization process (ksyncd) synchronizes the backup Routing Engine
7.
with the master Routing Engine.
After ksyncd completes the synchronization, all state information and the forwarding
8.
table are updated.
Figure 2 on page 7 shows the effects of a switchover on the routing (or switching
)platform.
command from the Backup Routing Engine
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command from the