Dell POWEREDGE M1000E - Manual (Page 78)

58 Access Gateway Administrator’s Guide
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Trunking in Access Gateway mode
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Trunking in Access Gateway mode
The hardware-based Port Trunking feature enhances management, performance, and reliability of
Access Gateway N_Ports when they are connected to Brocade fabrics. Port trunking combines
multiple links between the switch and AG module to form a single, logical port. This enables fewer
individual links, thereby simplifying management. This also improves system reliability by
maintaining in-order delivery of data and avoiding I/O retries if one link within the trunk fails.
Equally important is that framed-based trunking provides maximum utilization of links between the
AG module and the core fabric.
Trunking allows transparent failover and failback within the trunk group. Trunked links are more
efficient because of the trunking algorithm implemented in the switching ASICs that distributes the
I/O more evenly across all the links in the trunk group.
Trunking in Access Gateway is mostly configured on the Edge switch. To enable this feature, you
must install the Brocade ISL license on both the Edge switch and the module running in AG mode
and ensure that both modules are running the same Fabric OS version. If a module already has an
ISL trunking license, no new license is required. After the trunking license is installed on a switch in
AG mode and you change the switch to standard mode, you can keep the same license.
NOTE
N_Port trunking is not supported to HBAs connected to switches running in Access Gateway mode.
N_Port trunking is only supported for HBAs connected to switches running in Native mode.
How trunking works
Trunking in Access Gateway mode provides a trunk group between N_Ports on the AG module and
F_Ports on the Edge switch module. With trunking, any link within a trunk group can go offline or
become disabled, but the trunk remains fully functional and no reconfiguration is required.
Trunking prevents reassignments of the port ID when N_Ports go offline.
Configuring trunking on the Edge switch
Because AG trunking configuration is mostly on the Edge switch, information in this section is
applicable to the Edge switch module and not the AG module. On the AG module, you only need to
ensure that the trunking license is applied and enabled. On the Edge switch, you must first
configure an F_Port trunk group and statically assign an Area_ID to the trunk group.
Assigning a
Trunk Area (TA) to a port or trunk group enables F_Port masterless trunking on that port or trunk
group. On switches running in Access Gateway mode, the masterless trunking feature trunks
N_Ports because these are the only ports that connect to the Enterprise fabric. When a TA is
assigned to a port or trunk group, the ports will immediately acquire the TA as the area of its port
IDs (PIDs). When a TA is removed from a port or trunk group, the port reverts to the default area as
its PID.
NOTE
By default, trunking is enabled on all N_Ports of the AG; ensure that this feature is enabled on
N_Ports that are part of a port trunk group.