Reference Guide

Fabric parameter considerations
By default, EX_Ports and VEX_Ports detect, autonegotiate, and configure the fabric parameters without user intervention. You can
optionally configure these parameters manually.
∙ To change the fabric parameters on a switch in the edge fabric, use the configure command.
Note that to access all of the fabric parameters controlled by this command, you must disable the switch using the
switchDisable command. If executed on an enabled switch, only a subset of attributes is configurable.
∙ To change the fabric parameters of an EX_Port on the FC router, use the portCfgEXPort command.
∙ To change the fabric parameters of a VEX_Port, use the portCfgVEXPort command.
The backbone fabric PID mode and the edge fabric PID mode do not need to match, but the PID mode for the EX_Port or VEX_Port
and the edge fabric to which it is attached must match. You can statically set the PID mode for the fabric by using the -p option with the
portCfgEXPort command. Use the -t option to disable the negotiate fabric parameter feature; otherwise, the PID mode is autonegotiated.
The various edge fabrics may have different PID modes.
Fabric parameter settings, namely, E_D_TOV (error-detect timeout value), R_A_TOV (resource-allocation timeout value), and PID
format, must be the same on EX_Ports or VEX_Ports and on the fabrics to which they are connected. You can set the PID format on an
EX_Port when you configure an inter-fabric link.
The default values for E_D_TOV and R_A_TOV for an EX_Port or VEX_Port must match those values on other Fabric OS switches. You
do not need to adjust these parameters for an EX_Port or VEX_Port unless you have adjusted them for the edge fabric.
The default values for R_A_TOV and E_D_TOV are the recommended values for all but very large fabrics (ones requiring four or more
hops) or high-latency fabrics (such as ones using long-distance FCIP links).
Inter-fabric broadcast frames
The FC router can receive and forward broadcast frames between edge fabrics and between the backbone fabric and edge fabrics.
Many target devices and HBAs cannot handle broadcast frames. In this case, you can set up broadcast zones to control which devices
receive broadcast frames. (Refer to Broadcast zones on page 303 for information about setting up broadcast zones.)
By default, broadcast frames are not forwarded from the FC router to the edge fabrics.
Displaying the current broadcast configuration
1. Log in to the FC router as admin.
2. Enter the following command:
fcr:admin> fcrbcastconfig --show
This command displays only the FIDs that have the broadcast frame option enabled. The FIDs that are not listed have the
broadcast frame option disabled.
Enabling broadcast frame forwarding
1. Log in to the FC router as admin.
2. Enter the following command:
fcr:admin> fcrbcastconfig --enable -f fabricID
The fabricID variable is the FID of the edge or backbone fabric on which you want to enable broadcast frame forwarding.
Broadcast frame forwarding is enabled by default.
Using FC-FC Routing to Connect Fabrics
Brocade Fabric OS Administration Guide, 8.0.1
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