2.5.2 - Force10 Networks

Chapter 15 Port Mirroring
This chapter contains the following sections:
• Port Mirroring Features
• Port Mirroring Commands on page 250
• Port Mirroring Configuration Examples on page 250
• Verifying Port Mirroring on page 252
Port Mirroring Features
• Enables you to monitor network traffic with an external network analyzer
• Forwards a copy of each incoming and outgoing packet to a specific port that you designate
• Is used as a diagnostic tool, debugging feature, or means of fending off attacks
• The mirrored port (also called a source port) can be a part of any VLAN, whereas the destination port
(also called a probe port or mirroring port) cannot be a VLAN member.
• In an S-Series stack, the mirrored port and destination port can be on separate stack members.
• A stack has a limit of one port mirroring session and one destination port. More than one mirrored port
can be designated, but the percentage of the source traffic accepted on the probe port is likely to
decline with each added source, depending on the amount of traffic — to roughly 50% each for two
source ports, 33% per port for three, and so on.
Inbound or outbound packets will switch to their destination and will be copied to the mirrored port.
Ports
sending
data to
mirrored
port
Mirrored Port
Probe Port
Figure 207 Port Mirroring Diagram
Switch
Ports
receiving
data from
mirrored
port
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