Standard Trunking Criteria; Ex_Port Trunking; Fabric Considerations - HP A7533A - Brocade 4Gb SAN Switch Base Administrator's Manual

The maximum number of ports per trunk and trunks per switch depends on the HP model.
NOTE: Director blade model FC10-6 does not support trunking.
For detailed information about trunking commands, see online help or the Fabric OS Command Reference.

Standard trunking criteria

Observe the following criteria for standard distance trunking:
• There must be a direct connection between participating switches.
• Trunk ports must reside in the same port group.
• Trunk ports must run at the same speed (either 2 Gbps, 4 Gbps, or 8 Gbps).
• Trunk ports must be set to the same ISL mode (L0 is the default). For details on extended ISL mode.
• Trunk ports must be E_Ports or EX_Ports.
• For optimal performance, cable lengths of no more than 30 meters difference are recommended.
• The switch.interopMode parameter must be set to 0. See
on page 505 for information and procedures related to interoperability mode.
• The port ISL mode must be disabled (using the portCfgIslMode command).

EX_Port trunking

In Fabric OS 5.2.0 and later, you can configure EX_Ports to use frame-based trunking just like regular
E_Ports. EX_Port frame based trunking has a "master" trunk link. If the master link goes down, the entire
trunk will re-form and it will be taken offline for a short period of time. The EX_Port restrictions are the same
as E_Ports. A trunk of E- or EX_Port can be up to 8-ports wide. All the ports must be adjacent to each other
using the clearly marked groups on the front of the product.

Fabric considerations

The ISL Trunking feature is provided with the Fabric OS and can be activated by entering a license key,
available from HP. When the ISL Trunking license is activated (after you have entered the
switchDisable and switchEnable commands), trunking is automatically implemented for any
eligible ISLs.
A license must be activated on each switch that participates in trunking.
To use ISL Trunking in the fabric, the fabric must be designed to allow trunking groups to form. To identify
the most useful trunking groups, evaluate the traffic patterns before designing or redesigning the fabric.
ISL Trunking can be used to simplify storage area network design and improve performance. When
designing the SAN, consider the following recommendations in addition to the standard guidelines for
SAN design:
• Evaluate the traffic patterns within the fabric.
• Place trunking-capable switches adjacent to each other.
This maximizes the number of trunking groups that can form. If you are using a core/edge topology,
place trunking-capable switches at the core of the fabric and any switches that are not trunking-capable
at the edge of the fabric.
• Activate an ISL Trunking license on each switch that is to participate in a trunking group.
• When connecting two switches with two or more ISLs, ensure that all trunking requirements are met to
allow a trunking group to form.
374 Administering ISL Trunking
"Implementing an Interoperable Fabric"