HP StorageWorks Fabric OS 5.3.x administrator guide (5697-0244, November 2009)

242 Using the FC-FC routing service
The default values for R_A_TOV and E_D_TOV are the recommended values for all but very large fabrics
(ones requiring four or more hops) or high-latency fabrics (such as ones using long-distance FCIP links).
Configuring EX_Port frame trunking (optional)
In Fabric OS v5.2.x or later, you can configure EX_Ports to use frame based trunking just as you do regular
E_Ports. EX_Port frame trunking support is designed to provide the best utilization and balance of frames
transmitted on each link between the FCR and the edge fabric. You should trunk all ports connected to the
same edge fabrics.
NOTE: FCR front domain has a higher node WWN—derived from the FC router—than that of the edge
fabric. Therefore, the FCR front domain initiates the trunking protocol on the EX_Port.
After initiation, the first port from the trunk group that comes online is designated as the master port. The
other ports that come online on the trunk group are considered the slave ports. Adding or removing a slave
port does not cause frame drop.
The restrictions for EX_Port frame trunking are the same as for E_Ports–all the ports must be adjacent to
each other using the clearly marked groups on the front of the product.
EX_Port frame-based trunking has a master trunk link. If the master trunk link goes down, the entire
EX_Port-based trunk will reform and it will be taken offline for a short period of time. If there are no other
links to the edge fabric from the backbone, the master port going offline may cause a traffic disruption in
the backbone.
If router port cost is used with EX_Port trunking the master port and slave ports share the router port of the
master port.
For information about setting up E_Port trunking on an edge fabric, see ”Administering ISL Trunking” on
page 359 in this guide.
Supported configurations and platforms
The EX_Port trunking is an FCR software feature and requires that you have the FCR trunking license
installed on the FCR switch and on the edge fabric connected to the other side of the trunked EX_Ports.
EX_Port trunking is supported only with Brocade edge fabrics. You can use EX_Port frame trunking in the
following configurations and cases:
• Ports speeds of 2 Gbit/sec up to a maximum speed of 4 Gbit/sec and trunking over long distance.
• In the edge fabric, when FCR is connected to a Condor-based switch (for example, the SAN Switch
4/32, SAN Switch 4/32B, 4/64 SAN Switch, or FC 4-48 blade) that supports eight ports from the
trunkable group.
• When FCR is connected to Bloom-based switches (for example, the SAN Switch 2/16, SAN Switch
2/32, SAN Director 2/128, or FC-16 blade) supporting four ports in the trunk group. If the edge fabric
is a Bloom-based switch, the FCR will setup the trunking for four ports per trunk.
• When FCR is connected to an edge fabric using a mix of trunked and non-trunked EX_Ports. All will
share the same front domain.
• With the Secure Fabric OS edge fabric.
High availability support
The EX_Port frame trunking feature also is a High Availability (HA) supported feature. The HA protocol for
EX_Port trunking is as follows:
• If trunking is disabled prior to the HA failover, it remains disabled after the HA failover.
• If trunking is enabled prior to the HA failover, it remains enabled after the HA failover.
Backward compatibility support
For backward compatibility, FCR that supports EX_Port trunking can continue to interoperate with older
FCR switches and all previously supported Brocade switches in the Brocade edge fabric.