Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 224)

196 Multi-Service IronWare Routing Configuration Guide
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Enabling and disabling NSR
Enabling and disabling NSR
To enable NSR for OSPF, enter the following command.
Brocade(config)# router ospf
Brocade(config-ospf-router)# nonstop-routing
To disable NSR for OSPF, enter the following command.
Brocade(config)# router ospf
Brocade(config-ospf-router)# no nonstop-routing
Syntax: [no] nonstop-routing
If you enter the graceful-restart command when NSR is already enabled, the command is rejected
with the following message:
Error - Please disable NSR before enabling Graceful Restart
Similarly, if you enter the nonstop-routing command when graceful restart is already enabled, the
command is rejected and the following message is displayed:
Error - Please disable Graceful Restart before enabling NSR
Limitations of NSR
Following are the limitations of NSR:
• Configurations that occur before the switchover are lost due to the CLI synchronization.
• Sham links are not supported.
• OSPF adjacency over GRE tunnels is not supported.
• Changes in the neighbor state or interface state before or during a switchover do not take
effect.
• Traffic counters are not synchronized because the neighbor and LSA database counters are
recalculated on the standby module during synchronization.
• LSA acknowledging is delayed because it has to wait until standby acknowledging occurs.
• Depending on the sequence of redistribution or new LSAs (from neighbors), the LSAs accepted
within the limits of the database may change after switchover.
• In NSR hitless failover, after switchover, additional flooding-related protocol traffic is generated
to the directly connected neighbors.
• OSPF startup timers, database overflow, and max-metric, are not applied during NSR
switchover.
Adding additional parameters
Previously, to add new parameters, the old configuration had to be undone and the newer
configuration had to be recreated. In release 04.1.00 however, to add new parameters, the existing
configuration need not be undone or removed. Any successive configuration changes with new
parameters is appended to the existing configuration. If the same parameter is entered again with
a different value, then the corresponding parameter value is updated.