HP StorageWorks 2/16V Brocade Fabric OS Command Reference Manual - Supporting - Page 376

2 linkCost linkCost Sets or displays the Fabric Shortest Path First (FSPF) cost of a link. Synopsis linkcost [[slotnumber/][portnumber] [cost]] Description Use this command to set or display the cost of an interswitch link (ISL). The cost of a link is a dimensionless positive number. The FSPF protocol compares the cost of various paths between a source switch and a destination switch by adding the costs of all the ISL's along each path. FSPF chooses the path with minimum cost. If multiple paths exist with the same minimum cost, FSPF employs load sharing over these paths. Every ISL has a default cost that is inversely proportional to its bandwidth. For a 1-Gbit/sec ISL, the default cost is 1000. For a 2-Gbit/sec ISL, the default cost is 500. This simple algorithm is not effective when dealing with trunking ISLs greater than 2 Gbit/sec and less than 1-Gbit/sec bandwidths. Table 16 lists the link cost defaults. TABLE 16 Link Cost Defaults Link type Link cost 2-Gbit/sec trunks 500 4-Gbit/sec ISL 500 10-Gbit/sec ISL 500 Operands This command can be used to set a non-default, "static" cost for any port except EX/VEX ports. (Use fcrRouterPortCost to configure EX/VEX ports). When executed without arguments, this command displays the current cost of each port on the switch, even those are not ISL's. Active ISLs have an additional suffix of E_PORT attached to their interface number. If the port has a static cost assigned to it, then the suffix of STATIC is appended to the link cost. In this case, only the current link cost is displayed. Use interfaceShow to display both the default and current link costs. To remove a static cost from the database, execute this command with a cost of zero on the desired port. This port will then revert to its default link cost. Valid cost values are 0 to 65,535. Assigning a value outside this range displays an error message and rejects the value. The execution of this command is subject to Admin Domain restrictions that may be in place. This command has the following operands: slotnumber For bladed systems only, specify the slot number of the port to display, followed by a slash (/). portnumber Specify the port number to display, relative to its slot for bladed systems. Use switchShow to list valid ports. This operand is optional; if omitted, the cost of all ports is displayed. 344 Fabric OS Command Reference Manual 53-1000436-01