Lucent Technologies P550 - Manual (Page 284)

Analyzing Network Performance Using RMON and Ethernet Statistics (Layer 2 & Layer 3)
17 -8 Cajun P550/P220 Switch Operation Guide
Note: Sampling only applies to inbound traffic.
Piggyback Port Port used to enable bi-directional port mirroring. If no piggyback
port is specified, only received traffic from the source port will go to
the mirror port. The piggyback port should have the same
bandwidth as the source port. Only one port per fabric can be used
as a piggyback port. Sampling rates have no effect on transmitted
information.
Considerations:
• You cannot use a port that has been designated as a piggyback
port.
• Once a port has been designated as a piggyback port, the link
light is turned on, even if there is no connection on the selected
port.
• The piggyback port is displayed in place of the source port in the
VLAN menu.
• If the source and piggyback ports are at a higher bandwidth than
the mirror port’s bandwidth, the traffic on the source port may
exceed the bandwidth that the mirror port can handle.
• The piggyback port will always show that it is using multi-layer
tagging.
• A spanning tree topology change occurs when you change a
piggyback port.
• Piggyback ports display in certain views of the Cajun P550
Switch user interface where you typically expect to find
information about a source port.
For example, the VLAN Switch Ports list, which displays the list
of ports associated with a VLAN, includes the piggyback port but
not the source port.
In the Intelligent Multicast Session Search and Static Multicast
Sessions views, the piggyback port displays in place of the
source port when piggyback port mirroring is enabled.
Note: To mirror outbound traffic only, select a source, mirror, and
piggyback port. Set the sampling to disable. Since disabling sampling
only applies to inbound traffic, only outbound traffic is received.
Sampler Type Selects how often you want the mirror port to receive traffic
samples:
• Always - sends all samples.
• Periodic - sends samples at the interval described below.
• Disabled - shuts off traffic samples to the mirror port, but keeps
the association intact.
Sampling
Interval Displays the number of packets per second that are served by the
mirror port.
Table 17-3. Port Mirroring Configuration Parameters (Continued)
Parameter Definition