Brocade Troubleshooting and Diagnostics Guide v6.1.0 (53-1000853-01, June 2008)

Fabric OS Troubleshooting and Diagnostics Guide 75
53-1000853-01
Port mirroring
9
The bandwidth of the mirror port is unidirectional. The host (SID) talks to multiple storage
devices (DIDs) and does not send full line rate to a single target. A mirror port configured at
2GB can only support up to 2GB of traffic. A normal 2G F_Port is bidirectional and can support
up to 4GB of traffic (two to transmit and two to receive). If the mirror port bandwidth is
exceeded, the receiver port is not returned any credits and the devices in the mirror
connection see degraded performance.
• Deleting a port mirroring connection with In Order Deliver (IOD) enabled causes frame drop
between two endpoints.
• Using the firmware download procedure to downgrade to previous Fabric OS releases that do
not support port mirroring requires that you remove all the port mirroring connections. If you
downgrade to a previous versions of Fabric OS, you cannot proceed until the mirroring
connections are removed.
Port mirroring management
The method for adding a port mirror connection between two local switch ports and between a
local switch port and a remote switch port is the same. First you must configure a port to be a
mirror port before you can perform a portMirror
--add, or portMirror --delete.
Configuring a port to be a mirror port
• Type portCfg mirrorport [slot number/]<port number> --enable.
NOTE
The enable command enables the port as mirror port. The disable command disables the mirror port
configuration.
Adding a port mirror connection
1. Log in to the switch as admin.
2. Type portMirror
--add slotnumber/portnumber SourceID DestID
NOTE
The lower 8 bits of the address is ignored. For example, the ALPA for loop devices.
The configuration database keeps information about the number of port mirror connections
configured on a switch, the number of chunks of port mirroring data that are stored, and the chunk
number. When removing a mirror connection, always use this method to ensure that the data is
cleared. Deleting a connection removes the information from the database.
Deleting a port mirror connection
1. Log in to the switch as admin.
2. Type portMirror
--del SourceID DestID.
For example, to delete the port mirror connection on mirror port 2, you might type:
portMirror --del 0x011400 0x240400