Emulex 375 - Manual (Page 40)

E MULEX M ODEL 375 SAN S TORAGE S WITCH
U SER ’ S G UIDE C HAPTER 3: S WITCH M ANAGEMENT
E MULEX C ORPORATION 37
P ART N UMBER 00041369-002 R EV . B
Diagnostics
The following settings are available.
Setting Description
Port Control The method for controlling a port. Options include:
• auto – the default setting. The switch will automatically insert a
port based on policy settings. This prevents the insertion of
incompatible ports, which may cause disruption.
• bypass – removes a port from the network. Use this mode to
keep a device out of an initialization cycle when
troubleshooting.
• extLoopback – removes a port from the network and routes the
port's receive signal back through the port's transmitter. Use
this mode to isolate a specific zone for troubleshooting or to
test a transceiver’s circuitry and attached media from the node
end.
• insert – allows ports whose transceivers cannot derive a valid
clock or "K" character (Ordered Set) to join a zone. Use this
mode cautiously – devices without valid characters may put
bad data into a zone, causing the zone to go down.
Bypass on Clock Delta The switch determines the relative frequency of the signal being
received by a port to the internal switch clock. The result of this
test allows the determination of how far apart in frequency the
switch’s clock is in relation to the clock of the received signal –
the clock delta. If the clock delta exceeds a set threshold, the
switch is notified and the port may be bypassed if necessary.
Typically, clock drift is slow enough to allow the removal and
replacement of a defective part before the defective part begins
to affect system performance.