Users Guide

462 Fabric OS Administrator’s Guide
53-1002920-02
Understanding D_Port
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Table 76 summarizes D_Port test initiation modes and test start behavior.
When the tests complete, the port behavior depends on the mode:
• For static D_Ports, you must remove the D_Port configuration at either or both ends of the link
to bring up the port as a regular E_Port or F_Port.
• For a switch port in dynamic D_Port mode, the port automatically reverts back to an F_Port or
an E_Port, if the port at the other end reverts to a regular port.
General limitations and considerations for D_Port
• The link to be tested must be marginally functional and able to carry a minimal number of
frames before it can become a D_Port link. The D_Port feature is useful for diagnosing
marginal faults only; it cannot detect the complete failure of any component.
• On QSFP+ ICL ports that are configured as D_Ports, only link traffic can be run. Electrical and
optical loopback tests are not supported.
• Brocade recommends that D_Port tests be limited to a maximum of eight D_Ports at once.
Otherwise, there is a possibility of false alarms.
• When a large number of D_Ports are configured, the test is run on one port per blade at a time,
and other ports wait until the test is completed. No test begins until the fabric is stable.
• Note the following High Availability (HA) considerations:
- There is no HA support for D_Port test options and results. Consequently, such information
is not synchronized with the standby side. Any information from a previous test is lost
following a failover.
- During an HA failover and reboot on one side of the link, the link goes through
reinitialization and may restart the test. However, the test cannot proceed if the remote
port is not ready to proceed further (the remote port may already be done with the D_Port
test and in final state). In such a case, the test will eventually fail with “Remote port not
ready”. Restarting the test from either side will recover the port.
• D_Ports on an Access Gateway are supported only when there is no mapping between F_Ports
and N_Ports; this includes static mapping and preferred port mapping. In addition, device
(WWN) mapping is also not retained when a D_Port is used. If an Access Gateway port to be
tested is mapped, the port mapping (including static and preferred port mapping) must be
removed before the D_Port can be used. (Refer to “Saving port mappings on an Access
Gateway” on page 464.)
• Access Gateway does not support D_Port dynamic mode. If the port on the connected switch or
adapter is configured as a D_Port, the Access Gateway port is not automatically enabled as a
D_Port. The D_Port must be configured on the Access Gateway port in static mode.
TABLE 76 D_Port configuration mode and nature of test
D_Port mode/nature of test Description
Mode Static User configures port explicitly. Port remains as D_Port until user removes
configuration.
Dynamic No user configuration required. D_Port mode is initiated by external request from
remote port.
Nature of test Automatic Test automatically starts when the port comes online.
Manual User starts test from switch side (using the portdporttest - -start command) or from
HBA side (refer to “BCU D_Port commands” on page 468).