Administrator Guide

474 Fabric OS Administrator’s Guide
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EX_Port frame trunking configuration
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EX_Port frame trunking configuration
In Fabric OS v5.2.0 and 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 FC router and the edge fabric. You should
trunk all ports connected to the same edge fabrics.
The FC router front domain has a higher node WWN—derived from the FC router—than that of the
edge fabric. Therefore, the FC router 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; however, removing a slave port causes the loss
of frames in transit.
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.
ATTENTION
This feature should be enabled only if the entire configuration is running Fabric OS v5.2.0 or later.
If router port cost is used with EX_Port trunking, the master port and slave ports share the router
port cost of the master port.
For information about setting up E_Port trunking on an edge fabric, see Chapter 19, “Managing
Trunking Connections,” in this guide.
Masterless EX_Port trunking
Starting in Fabric OS 6.3.0, EX_Port frame-based trunking is masterless. This means that if the
master port goes offline, one of the slave ports automatically becomes the new master port and all
of the other slave ports stay online, thus avoiding traffic disruption. The new master port uses the
old master port area and the old master port is assigned a new, unused area. In this way, the PID of
the trunk does not change if the master port goes offline.
Masterless EX_Port trunking is supported only on EX_Ports in the following platforms:
• Brocade DCX and DCX-4S (FC8-16, FC8-32, FC8-48, FC8-64, FS8-18, or FX8-24)
• Brocade 5100 switch
• Brocade 5300 switch
• Brocade VA-40FC switch
• Brocade Encryption Switch
For the Brocade DCX and DCX-4S, Virtual Fabrics must be enabled for masterless EX_Port trunking
to take effect. For the Brocade 5100, 5300, VA-40FC, and Brocade Encryption Switch, Virtual
Fabrics can be enabled or disabled.
For EX_Ports on the Brocade 7500 or the FR4-18i blade, or for EX_Ports on the Brocade DCX or
DCX-4S with Virtual Fabrics mode disabled, masterless EX_Port trunking is not in effect. In this
situation, if the master port goes offline, the entire EX_Port-based trunk re-forms and is 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.