Cisco ASA 5505 User Manual

Page 1311

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62-5

Cisco ASA 5500 Series Configuration Guide using the CLI

Chapter 62 Configuring Active/Standby Failover

Information About Active/Standby Failover

Table 62-2

shows the failover action for each failure event. For each failure event, the table shows the

failover policy (failover or no failover), the action taken by the active unit, the action taken by the
standby unit, and any special notes about the failover condition and actions.

Table 62-2

Failover Behavior

Failure Event

Policy

Active Action

Standby Action

Notes

Active unit failed (power or
hardware)

Failover

n/a

Become active

Mark active as
failed

No hello messages are received on
any monitored interface or the
failover link.

Formerly active unit recovers

No failover

Become standby

No action

None.

Standby unit failed (power or
hardware)

No failover

Mark standby as
failed

n/a

When the standby unit is marked as
failed, then the active unit does not
attempt to fail over, even if the
interface failure threshold is
surpassed.

Failover link failed during
operation

No failover

Mark failover
interface as failed

Mark failover
interface as failed

You should restore the failover link
as soon as possible because the
unit cannot fail over to the standby
unit while the failover link is down.

Failover link failed at startup

No failover

Mark failover
interface as failed

Become active

If the failover link is down at
startup, both units become active.

Stateful Failover link failed

No failover

No action

No action

State information becomes out of
date, and sessions are terminated if
a failover occurs.

Interface failure on active unit
above threshold

Failover

Mark active as
failed

Become active

None.

Interface failure on standby
unit above threshold

No failover

No action

Mark standby as
failed

When the standby unit is marked as
failed, then the active unit does not
attempt to fail over even if the
interface failure threshold is
surpassed.

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