Avaya Cajun P882 User Manual page 612

Chapter 19
Table 19-3. Port Mirroring Configuration Web Page Parameters
Parameter Definition
Piggyback Port used to enable bi-directional port mirroring. If no piggyback port is specified,
Port 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.
Note:
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 P550R 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.
• 80 series modules do not support piggyback ports.
• Fabric mode 1 port mirroring works with 50 series modules. Fabric mode 2 port
mirroring works with 80 series modules.
• If you set up a piggyback port, multicast traffic that is routed through the
mirrored port may be lost for a few minutes. This loss of multicast traffic is due
to the DVMRP routes that pass through the mirrored port entering hold-down
state. The default setting for the DVMRP hold-down period is 120 seconds.
Once this time expires, multicast traffic resumes.
• If you set up a port mirror with a piggyback port and the source port is a client
port for an intelligent multicast session, the port is removed from the multicast
session. Hosts that are attached to the client port stop receiving multicast traffic
until the port is either statically or dynamically added to the multicast session
again.
To avoid this interruption in multicast traffic, after setting up the port mirror:
• If the multicast session is a static session, add the client port to the session
• If the multicast session is a dynamic session, the client port is added to the
19-12
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.
again.
session again when the switch receives the next IGMP membership report.
Avaya P550R, P580, P880, and P882 Multiservice Switch User Guide, v5.3.1