EMC ED-12000B Switch User Manual


 
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EMC Connectrix DS-32B2 and ED-12000B Fabric OS Reference Manual
Telnet Commands
dlsReset
Turn off dynamic load sharing option.
Syntax
dlsReset
Availability Admin
Description Use this command to turn off DLS when a fabric change occurs.
Routing is generally based on the incoming port and the destination
domain. This means that all the traffic coming in from a port (either
E_Port or Fx_Port) directed to the same remote domain is routed
through the same output E_Port.
To optimize fabric routing, when there are multiple equivalent paths
to a remote switch, traffic is shared among all the paths. Load sharing
is recomputed when a switch is booted up or every time a change in
the fabric occurs. A change in the fabric is defined as an E_Port going
up or down, or an Fx_Port going up or down.
If DLS is turned off (using
dlsReset), load sharing is performed only
at boot time or when an Fx_Port comes up. Optimal load sharing is
rarely achieved with DLS disabled.
If DLS is turned on (using
dlsSet), routing changes can affect
working ports. For example, if an Fx_Port goes down, another
Fx_Port may be rerouted from one E_Port to a different E_Port. The
switch minimizes the number of routing changes, but some are
necessary in order to achieve optimal load sharing.
These changes can further affect the performance of the fabric if the
in-order delivery (IOD) option is on. With the IOD option (refer to the
iodSet command), routes are not available for a few seconds after a
fabric change. The time needed to reset the fabric routing varies
based on the size of the fabric. Some frame loss may occur because as
the fabric is recalculating routes, frames are dropped to avoid being
delivered out of order. No frame loss occurs if IOD is off, but there is
still a short period of time when traffic is not forwarded. This period
of time is significantly shorter than when IOD is on, and is usually
less than 1 second.
Use this command only if devices connected to the fabric cannot
handle occasional routing changes.
Operands None