HP StorageWorks 1606 Brocade Fabric OS Administrator's Guide v6.3.0 (53-100133 - Page 472

19 Trunking overview Re-initializing ports for trunking is required after you install the license so that the ports know that trunking is enabled. You can enable or disable trunking for a single port or for an entire switch. For trunking to work, individual ports or the entire switch must be set at the same speed and at the same mode, for example, 2 Gbps, 4 Gbps, 8 Gbps, or autonegotiate. For more information on setting port speeds, see "Trunking over long distance fabrics" on page 434. Figure 66 illustrates how trunking can result in more throughput by distributing data over four ISLs with no congestion. In a fabric that does not have trunking capability, some paths would be congested and other paths underutilized. FIGURE 66 Distribution of traffic over ISL Trunking groups Criteria for managing trunking connections Following is the criteria for managing trunking connections: • You can have up to eight ports in one trunk group to create high performance 32 Gbps ISL trunks between switches and up to 64 Gbps if there are eight ISLs with 8 Gbps each if 8 Gbps is supported. • Trunk links can be 2 Gbps, 4 Gbps, or 8 Gbps depending on the Brocade platform. • The maximum number of ports per trunk and trunks per switch depends on the Brocade platform. • There must be a direct connection between participating switches. • In Fabric OS v6.1.0 and later, you can configure EX_Ports to use frame-based trunking just like regular E_Ports. The EX_Port restrictions are the same as E_Ports. An E_Port or EX_Port trunk can be up to eight ports wide. All the ports must be adjacent to each other using the clearly marked groups on the front of the product See "EX_Port frame trunking configuration" on page 478 for additional information about EX_Port trunking. • The switch must be set to interopMode 0 for Brocade Native mode, which supports all stand-alone Brocade switches, but provides no interoperability support. See "Interoperability for Merged SANs" on page 291 for information and procedures related to interoperability. • The port ISL R_RDY mode must be disabled (using the portCfgIslMode command). Trunks operate best when the cable length of each trunked link is roughly equal to the others in the trunk. For optimal performance, no more than 30 meters difference is recommended. Trunks are compatible with both short wavelength (SWL) and long wavelength (LWL) fiber optic cables and transceivers. 430 Fabric OS Administrator's Guide 53-1001336-01