Endace DAG 4.5G2 Card, Руководство пользователя

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EDM 01-17 DAG 4.5G2/G4/GF Card User Guide
DAG 4.5GF
The diagram below shows the DAG 4.5GF card’s major components and
flow of data:
Extended
Functions
Failsafe Relays
The DAG 4.5GF has failsafe optical relays which allow you to connect the
two ports in the event of a power interruption or software or hardware failure
on the host. This means that in such an event the traffic can be switched to
bypass the DAG card while still maintaining network connectivity.
The failsafe relays are controlled via an optical switch on the DAG card and
can be configured to either fail-open or fail-closed.
Note: This feature is not available on the DAG 4.5G2/G4 cards.
Fail-Open
Fail-open is the default configuration and is for use in situations where the
nature of the event means that traffic must be stopped. In fail-open mode the
network connection will switch to open circuit in the event of a failure which
is effectively the same as disconnecting the DAG card from the network.
Fail-Closed
Fail-closed mode is for use in situations when the nature of the event means
that traffic must still flow. In this mode the two ports are connected together
so that all traffic received on Port A is transmitted on Port B and all traffic
received on Port B is transmitted on Port A.
Note: To implement the fail-closed mode you must engage the failsafe
relays using the
dagwatchdog
command. For further information on
using
dagwatchdog
please refer to Starting a Session in
Chapter 4: Capturing Data later in this User Guide.
©2005-2006 6 Version 4: August 2006