Copyright © 2010, Juniper Networks, Inc.
Known Behavior
35
Release 11.1.1
z
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.
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When you issue
show
commands as soon as the CLI is available after a stateful SRP
switchover, the commands can hang until the warm restart is completed.
Subscriber Interfaces
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MAC address validation is not supported on either of the following:
−
Packet-triggered subscriber interfaces that are created dynamically
−
Packet-triggered subscriber interfaces that are managed on the primary IP
interface
A packet-triggered subscriber interface is created when the router receives a packet
with an IP source address that does not match any entries in the demultiplexer table.
When the router detects an unmatched packet, it generates a trigger event that
determines whether to create a dynamic subscriber interface or configure an existing
interface. To configure packet detection on the router, use the
ip auto-detect
ip-subscriber
command.
System
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ERX routers display different behavior from E120 routers and E320 routers when
reporting modules as inactive.
ERX routers report a module as inactive when either:
−
The I/O module is not present
−
The primary line module is fully booted and ready to resume operation. In this
case, the standby is currently providing services.
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
