Configuring Port And Vlan Mirroring - Cisco 200 Series Administration Manual

Managing Device Diagnostics

Configuring Port and VLAN Mirroring

Configuring Port and VLAN Mirroring
STEP 1
Cisco Small Business 200 Series Smart Switch Administration Guide
• Output Power—Transmitted optical power.
• Input Power—Received optical power.
• Transmitter Fault—Remote SFP reports signal loss. Values are True, False,
and No Signal (N/S).
• Loss of Signal—Local SFP reports signal loss. Values are True and False.
• Data Ready—SFP is operational. Values are True and False
Port Mirroring is used on a network switch to send a copy of network packets
seen on one switch port, multiple switch ports, or an entire VLAN to a network
monitoring connection on another switch port. This is commonly used for network
appliances that require monitoring of network traffic, such as an intrusion-
detection system. A network analyzer connected to the monitoring port displays
the data packets for diagnosing, debugging, and performance monitoring. Up to
eight sources can be mirrored. This can be any combination of eight individual
ports and/or VLANs.
A packet that is received on a network port assigned to a VLAN that is subject to
mirroring, is mirrored to the analyzer port even if the packet was eventually
trapped or discarded. Packets sent by the switch are mirrored when Transmit (Tx)
Mirroring is activated.
Mirroring does not guarantee that all traffic from the source port(s) is received on
the analyzer (destination) port. If more data is sent to the analyzer port than it can
support, some data might be lost.
Only one instance of mirroring is supported system-wide. The analyzer port (or
target port for VLAN mirroring or port mirroring) is the same for all the mirrored
VLANs or mirrored ports.
To enable port and VLAN mirroring:
Click Administration > Diagnostics > Port and VLAN Mirroring. The
VLAN Mirroring Page
This page displays the following fields:
• Destination Port—Port to which traffic is to be copied; the analyzer port.
opens.
9
Port and
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