HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

372 Administering ISL trunking
Setting port speeds
For long-distance ports, if a port is set to autonegotiate port speed, the maximum speed (8 Gbps) is
assumed for reserving buffers for the port. If the port is running at only 2 Gbps, this wastes buffers. For
long-distance ports, it is best to set the port speed (this applies to the 4/32 SAN Switch, 4/32B SAN
Switch and the 4/256 SAN Director only).
On the HP StorageWorks 4/8 SAN Switch, 4/16 SAN Switch, 8/8 SAN Switch, 8/24 SAN Switch, SAN
Switch 4/32, 4/32B SAN Switch 4/256 SAN Director, 4/64 SAN Switch, DC Director, 8/40 SAN
Switch, and 8/80 SAN Switch platforms, for long-distance ports, you should specify the port speed instead
of setting it to autonegotiate. See Table 78 for long-distance mode definitions.
IMPORTANT: Support for 8 Gbps is only between the HP StorageWorks 4/256 SAN Director to the DC
Director enterprise-class platform or between HP StorageWorks DC Director-to-DC Director enterprise-class
platforms with the appropriate blades, the 8/8 SAN Switch, 8/24 SAN Switch, 8/40 SAN Switch, 8/80
SAN Switch, 8 Gb SAN Switch for HP BladeSystem c-Class, and the 8 Gbps supported SFPs installed.
The 8/8 SAN Switch, 8/24 SAN Switch, 8/40 SAN Switch, and 8/80 SAN Switch support long-distance
modes L0, LE, LS, and LD. The distance supported on each platform depends on the available buffers,
number of back-end ports, and number of offline ports.
You can set the port speed for one port or for an entire switch. Trunked ports must be set to the same
speed.
To set the speed for one port:
1. Connect to the switch and log in as admin.
2. Issue the portCfgSpeed command:
portcfgspeed [slotnumber/]portnumber, speed_level
where:
• slotnumber, for bladed systems only, specifies the slot number of the port to be configured, followed
by a slash (/). This operand is only required for Directors.
• portnumber specifies the port number relative to its slot for bladed systems.
• speedlevel specifies the speed of the link:
• 0—Autonegotiating mode. The port automatically configures for the highest speed.
• 1—one Gbps mode. Fixes the port at a speed of one Gbps. Changing the speed to one Gbps
causes the port to be excluded from the trunk group.
Table 78 Long-distance mode definitions
Long-distance mode Distance Comments
L0 Normal Normal mode. More than one
data Virtual Channel is used. All
other modes use one data Virtual
Channel.
LE Up to 10Km Reserves the buffers for 10 km
LS Static The distance statically specified
by you.
LD Auto distance detect Reserves buffers for distance
specified in the CLI. Fabric OS
6.1.x supports up to 500 km at
1G up to 250 km at 2G, and
100 km at 4G and 8G.