Juniper JUNOSe 10.3.2, Руководство по выпуску

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JunosE 10.3.2 Release Notes
32 „
Known Behavior
Stateful SRP Switchover (High Availability)
„ Additional processing is required to maintain and mirror the necessary state
information that enables subscriber sessions to stay up across an SRP failover.
As a result, the performance of other control plane functions is reduced.
Specifically, call setup rates are lower than in previous releases.
We have ongoing development activities to characterize and improve call setup
rates in future releases.
„ Stateful SRP switchover remains inactive for 20 minutes after an initial
cold-start or cold-restart of the router. This delay enables the system to reach a
stable configuration before starting stateful SRP switchover.
If you want to override the 20-minute timer, turn high availability off by using
the
mode file-system-synchronization command, and then on again by using
the mode high-availability command.
„ After a stateful SRP switchover, each layer of the interface columns must
reconstruct its interfaces from the mirrored information. While the interfaces
are being reconstructed the SRP module cannot send or receive frames,
including the protocol frames that signal graceful restart behavior with OSPF
and IS-IS peers. If the configured hold time is too short, peers might mistakenly
declare the adjacency down during the time in which the graceful restart is
taking place. [Defect ID 65132]
Work-around : Increase the hold time to provide sufficient time for interface
synchronization before the peers declare the adjacency down.
„ For OSPF, use the ip ospf dead-interval command to set the hold time. We
recommend that you use Bidirectional Forwarding Detection (BFD) with a
longer OSPF dead interval to achieve fast failure detection.
„ For IS-IS, use the isis hello-interval and isis hello-multiplier commands to
set the hold time.
We recommend the following hold times for each protocol, based on the
number of interfaces.
NOTE: Rapid call setup rates are most important following an outage that causes all
subscribers to drop, because many of the dropped subscribers will immediately
attempt to reconnect. This type of outage occurs far less frequently with stateful
SRP switchover.
Interface Count
Recommended Hold Time
for OSPF Recommended Hold Time
for IS-IS
16000 or less 80 seconds 50 seconds
16001 to 32000 87 seconds 55 seconds
32001 to 48000 90 seconds 70 seconds