Contemporary Control Systems Compact Managed Switches Software Manual for Web Browser - Manual (Page 20)

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4.4.3 Configure Port Mirroring
Port mirroring allows a port to copy or “mirror” traffic for one or many ports — useful
when a diagnostic tool is used. Switches normally send frames only to ports involved in
a conversation, so mirroring is required if a diagnostic tool must capture network traffic.
Various settings control how data is mirrored, but apply only if (in Figure 16, upper panel)
the Status option is enabled and a Mirror Port (to which the data is copied) is specified.
Ingress (Ingoing) Mirroring Rules (centre panel) apply to data received by the Source
Ports being mirrored; Egress (Outgoing) Mirroring Rules (lower panel) for data sent
by Source Ports being mirrored. Both sets of rules allow a MAC Address Filter and a
MAC Address to be defined. The Divider specifies the fraction of frames copied from
each source port.
The
MAC Address options are:
All — mirrors all traffic regardless of MAC address. This is the default.
Source — mirrors frames whose source addresses match the entered value.
Destination — mirrors frames whose destination addresses match the entered value.
Figure 16 — Configure Port Mirroring for 8-port Models
Figure 16 is for an 8-port model. A 16- or 24-port screen would be similar but simply
display more ports. The example has ports 2 and 3 as Ingress Source Ports and port 4
as the sole Egress Source Port — all to be copied to port 1. Since the Ingress Divider is
1, each frame from ports 2 and 3 will be mirrored — but only if its source address
matches 0050DBFF0000. The Egress Divider value is 10, so only 1 in 10 frames
transmitted by port 4 will be mirrored — and since the Egress MAC Address setting is
All, the source/destination address field in the transmitted frames will be ignored.