Enterasys Networks Enterasys D2 D2G124-12P - Manual (Page 135)

Port Mirroring
D-Series CLI Reference 4-31
Port Mirroring
The D‐Series device allows you to mirror (or redirect) the traffic being switched on a port for the
purposes of network traffic analysis and connection assurance. When port mirroring is enabled,
one port becomes a monitor port for another port within the device.
Mirroring Features
The D‐Series device supports the following mirroring features:
• Mirroring can be configured in a many‐to‐one configuration so that one target (destination)
port can monitor traffic on up to 8 source ports.
• Both transmit and receive traffic will be mirrored.
• A destination port will only act as a mirroring port when the session is operationally active.
• When a port mirror is created, the mirror destination port is removed from the egress list of
VLAN 1 after a reboot.
• MAC addresses will be learned for packets tagged with the mirror VLAN ID. This will
prevent the ability to snoop traffic across multiple hops.
Purpose
To review and configure port mirroring on the device.
Commands
show port mirroring
Use this command to display the source and target ports for mirroring, and whether mirroring is
currently enabled or disabled for those ports.
Syntax
show port mirroring
Parameters
None.
Caution: Port mirroring configuration should be performed only by personnel who are
knowledgeable about the effects of port mirroring and its impact on network operation.
Caution: Traffic mirrored to a VLAN may contain control traffic. This may be interpreted by the
downstream neighbor as legal control frames. It is recommended that you disable any protocols
(such as Spanning Tree) on inter-switch connections that might be affected .
For information about... Refer to page...
show port mirroring 4-31
set port mirroring 4-32
clear port mirroring 4-33