Port Mirroring - D-Link xStack DGS-3400 Series User Manual

xStack DGS-3400 Series Layer 2 Gigabit Ethernet Managed Switch

Port Mirroring

The Switch allows you to copy frames transmitted and received on a port and redirect the copies to another port. You can attach a
monitoring device to the mirrored port, such as a sniffer or an RMON probe, to view details about the packets passing through the
first port. This is useful for network monitoring and troubleshooting purposes. To view the Port Mirroring window, click Port
Mirroring in the Administration folder.
To configure a mirror port:
1. Select the Target Port on the Unit to which frames will be copied, which receives the copies from the source port.
2. Select the Source Direction, Ingress, Egress, or Both and change the Status drop-down menu to Enabled.
3. Click Apply to let the changes take effect.
NOTE: You cannot mirror a fast port onto a slower port. For example, if you try to mirror the
traffic from a 100 Mbps port onto a 10 Mbps port, this can cause throughput problems. The port
you are copying frames from should always support an equal or lower speed than the port to
which you are sending the copies. Also, the target port for the mirroring cannot be a member of
a trunk group. Please note a target port and a source port cannot be the same port.
NOTE: Target mirror ports cannot be members of a trunking group. Attempting to do so will
produce an error message and the configuration will not be set.
Figure 6- 19. Port Mirroring window
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