Viavi Apex Enterprise G3-APEX-ENT-32T, Руководство пользователя, Страница: 321 / 380

Software configuration
Chapter 15: Gen3 Capture Card 321
♦
Reconstructs an integrated data stream from the two channels
♦
Routes the integrated signal to the send channel of the SPAN/mirror port
Each of these activities burdens the switch’s internal processor. These demands
on the switch’s CPU have implications for both your monitoring equipment and
general network performance. Using a SPAN/mirror port to capture network
traffic for analysis presents the following risks:
♦
As total bandwidth usage for both channels exceeds the capacity of the
outbound link to the analyzer, the excess traffic is dropped from the
analyzer stream. There simply is not enough bandwidth to transmit both
sides of the full-duplex traffic across a single standard interface.
♦
The switch’s CPU must act as both a network switch and a packet-copier.
The switch’s CPU must also integrate the two data streams (send and
receive) together correctly. Both packet copy/re-direction and channel
integration is affected by switch load. This means the SPAN/mirror port
may not deliver accurate captures when the switch is under heavy load.
Monitoring a 10/100 network through a Gigabit SPAN/mirror port and
analyzer does not alleviate these concerns. Also, there is no notification
when the SPAN/mirror port is dropping packets or delivering inaccurate
time stamps.
A SPAN/mirror port can deliver satisfactory results when used to monitor lightly
used, non-critical networks. If network utilization exceeds the capacity of the
outbound (analyzer) link, packet loss results—which invalidates many types of
analysis, and makes monitoring for certain kinds of network activity impractical.
For example, you might miss a virus signature because packets are being
dropped. When analyzing a transaction or connection problem, the analyzer may
detect problems where none exist because expected packets are being dropped
by the SPAN/mirror port. Hardware and media errors will also be impossible to
troubleshoot through a SPAN/mirror port, as these errors are not mirrored to the
analyzer.
Software configuration
The Gen3 capture card hardware unlocks certain features in Observer/GigaStor.
You can configure and use these settings inside the Observer application and
Windows Device Manager.
How to view the capture card properties
Viewing the Gen3 capture card properties allows you to verify what you think is
happening at the card level (such as SFP activity, link speed, auto-negotiation) is
actually happening. Additionally, configuration changes to the card can be made
here.
Tip! These settings can be viewed remotely using Windows RDP or an
equivalent remote desktop application. You might find this useful for
checking SFP and link states when physical access to the GigaStor is not
feasible.
Some benefits of viewing the Gen3 capture card properties include:
♦
Verifying if an SFP...
●
is present and in which port.