Brocade Fabric OS Troubleshooting and Diagnostics Guide v6.2.0 (53-1001187-01, April 2009)

80 Fabric OS Troubleshooting and Diagnostics Guide

53-1001187-01

Port mirroring

• FC4-16 16-port blade

• FC4-48 48-port blade

• FC8-16 16-port blade

• FC8-32 32-port blade

• FC8-48 48-port blade

• FA4-18 application blade

• FR4-18i routing and FCIP blade

• FC4-16IP iSCSI blade on Fibre Channel ports only

The FC4- and FC8-48 implement port pairing, meaning that two ports share the same area.

Port pairing uses a single area to map to two physical ports. A frame destined to the secondary

port is routed to the primary port. The primary port's filtering zone engine is used to redirect

the frame to the secondary port. Port mirroring uses the port filter zone engine to redirect the

frames to the mirror port. If two F_Ports share the same area, both ports cannot be part of a

mirror connection. One of the two ports can be part of the connection as long as the other port

is offline. Supported port configurations are shown in Table 13.

If IOD is enabled, adding or deleting a port mirror connection causes a frame drop. Port

mirroring reroutes a given connection to the mirror port, where the mirror traffic takes an extra

route to the mirror port. When the extra route is removed, the frames between the two ports

goes directly to the destination port. Since the frames at the mirror port could be queued at the

destination port behind those frames that went directly to the destination port, port mirroring

drops those frames from the mirror port when a connection is disabled. If IOD has been

disabled, port mirroring does not drop any frames but displays an IOD error.

• A port cannot be mirrored to multiple locations. If you define multiple mirror connections for

the same F_Port, all the connections must share the same mirror port.

• Local switches cannot be mirrored because FICON CUP frames to a local switch are treated as

well-known addresses or embedded frame traffic.

• Using firmware download to downgrade to previous Fabric OS releases that do not support port

mirroring requires that you remove all port mirroring connections.

Port mirroring considerations

Before creating port mirror connections, consider the following limitations:

• A mirror port can be any port on the same switch as the source identifier port.

• Only one domain can be mirrored per chip; after a domain is defined, only mirror ports on the

defined domain can be used.

TABLE 13 Port combinations for port mirroring

Primary port Secondary port Supported

F_Port F_Port No

F_Port Offline Yes

Offline F_Port Yes

F_Port E_Port Yes

E_Port F_Port Yes

E_Port E_Port No