Owner's Manual
460
Redundant Routing Engine (RE) Support
This driver offers Redundant Routing-Engine Support. For routers with redundant Routing
Engines (RE), you can configure a master and backup RE. By default, the RE in slot RE0 is the
master, and the RE in slot RE1 is the backup. The backup RE ill assume mastership once a loss
signal is detected from the master. See Configure -> Redundancy on page 462 for more
information.
Graceful Restart Engine Switchover allows the change from one RE to a fail over routing engine by
keeping the forwarding data on both routing engines. This allows in-service software upgrades. You
can also enable automatic synchronization of the two configurations.
Following Router Models support Redundant Routing-Engines: M10i, M20, M40
M160E, T320, T640. JunOS version 5.5 or greater supports redundancy.
Failover Sequence
The following describes the routing engine failover sequence:
1
After keepalive loss for a specified period, the driver logs a message.
2
After keepalive loss for a specified period seconds, the backup RE attempts to become master.
Whenever the backup RE is active the application generates an alarm, and the display
updates with the current status.
3
Once the backup RE becomes master, it continues to function as master even after the
originally configured master RE has successfully resumed operation. You must manually
restore it to its previous backup status. However, if at any time one of the REs is not present,
the other RE becomes master automatically, regardless of how redundancy is configured.
The driver is listening for the following notification from the router:
1.3.6.1.4.1.2636.4.1.4
The jnxRedundancySwitchover defined in min JUNIPER-MIB.
When received, the driver attempts to determine which routing engine (RE) is the current master
based on var bind content. The management interfaces are updated based on the configured IP
address for that RE which would have been recorded in the database on the last resync.
You can view what the recorded IP is for each RE from the Routing Engine screen under Discrete
Config in the redundancy view. (See Configuring Routing Engines on page 463.)
For this to work the router needs to be configured to send this application a v2 notification of the
above mentioned OID. In testing, the following configuration under SNMP receives this
notification:
trap-group redcell {
version v2;
categories {
chassis;