Users Guide

Fabric OS Administrator’s Guide 111
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Enabling forward error correction
3
Setting the behavior for handling duplicate PWWNs
1. Connect to the switch and log in using an account with admin permissions.
2. Enter the switchDisable command to disable the switch.
3. Enter the configure command.
4. Enter y after the F_Port login parameters prompt.
F-Port login parameters (yes, y, no, n): [no] y
5. Enter one of the following options at the Enforce FLOGI/FDISC login prompt to select the
behavior for handling duplicate PWWNs.
• Enter 0 to have the first login take precedence over the second login (default).
• Enter 1 to have the second login override the first login.
• Enter 2 to have the port type determine the behavior.
If a duplicate login is received on an F_Port, the duplicate login is rejected and the old
login is preserved; if a duplicate login is received on an NPIV port, the newer login is
accepted.
Enforce FLOGI/FDISC login: (0..2) [0] 1
6. Respond to the remaining prompts, or press Ctrl + D to accept the other settings and exit.
7. Ente r th e switchEnable command to re-enable the switch.
With any of these settings, detection of duplicate PWWNs results in a RASLog. Ports that are
restricted become persistently disabled, marked with the reason “Duplicate Port WWN detected”.
Enabling forward error correction
Forward error correction (FEC) provides a data transmission error control method by including
redundant data (error-correcting code) to ensure error-free transmission on a specified port or port
range. When FEC is enabled, it can correct one burst of up to 11-bit errors in every 2112-bit
transmission, whether the error is in a frame or a primitive.
The following considerations apply to FEC:
• FEC is supported on E_Ports on 16 Gbps-capable switches.
• FEC is supported on the N_Ports and F_Ports of an access gateway using RDY, Normal
(R_RDY), or Virtual Channel (VC_RDY) flow control modes.
• FEC is supported on F_Ports on a switch if the device attached supports FEC by using a
Brocade host bust adaptor (HBA) ).
• FEC is enabled by default.
TABLE 11 Duplicate PWWN behavior: Port type determines which login takes precedence
Input port First port login is NPIV port First port login is F_Port
FLOGI received New login forces an explicit logout of original
FDISC on the previous NPIV port.
New login is rejected and the new port is
persistently disabled.
FDISC received New FDISC forces an explicit logout of original
FDISC on the previous NPIV port.
New FDISC is rejected.