Fabric OS Reference Manual

116 Fabric OS Reference Manual
linkCost
Set or print the FSPF cost of a link.
Synopsis
linkCost [portnumber], [cost]
Availability admin
Description Use this command to set or display the cost of an Inter-Switch Link (ISL).
The cost of a link is a dimensionless positive number. It is used by the FSPF
path selection protocol to determine the path that a frame takes going from
the source to the destination switch. The chosen path is the path with
minimum cost. The cost of a path is the sum of the costs of all the ISLs
traversed by the path. The cost of a path is also known as the “metric”.
FSPF supports load sharing over a number of equal cost paths.
Every ISL has a default cost that is inversely proportional to the bandwidth
of the ISL. For a 1 Gb/s ISL, the default cost is 1000.
This command changes the actual link cost only; it does not affect the
default cost. The
interfaceShow
command displays both the default and
the actual cost.
Without operands, this command displays the actual cost of all the ISLs.
With one operand, it displays the actual cost of a specific ISL. With two
operands, it sets the cost of a specific ISL.
Operands This command has the following operands:
portnumber
Specify the interface cost to be set or printed. This
operand is optional.
cost
Specify the new cost of the link connected to interface
portnumber
. This operand is optional.