Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

428 Fabric OS Administrator’s Guide
53-1002148-02
Trunking overview
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Types of trunking
Trunking can be between two switches, between a switch and an Access Gateway module, or
between a switch and a Brocade adapter. The types of trunking are as follows:
• ISL trunking, or E_Port trunking, is configured on an inter-switch link (ISL) between two Fabric
OS switches and is applicable only to E_Ports.
• ICL trunking is configured on an inter-chassis link (ICL) between two enterprise-class platforms
and is applicable only to ports on the core blades.
• EX_Port trunking is configured on an inter-fabric link (IFL) between an FC router (EX_Port) and
an edge fabric (E_Port). The trunk ports are EX_Ports connected to E_Ports.
See “EX_Port frame trunking configuration” on page 480 for additional information about
EX_Port trunking.
• F_Port trunking is configured on a link between a switch and either an Access Gateway module
or a Brocade adapter. The trunk ports are F_Ports (on the switch) connected to N_Ports (on the
Access Gateway or adapter).
• N_Port Trunking is configured on a link between a switch and either an Access Gateway
module or a Brocade adapter. It is the same as F_Port trunking. The trunk ports are N_Ports
(on the Access Gateway or adapter) connected to F_Ports (on the switch).
For more information, see “Configuring F_Port trunking for Brocade adapters” on page 444,
the Access Gateway Administrator’s Guide, and the Brocade Adapters Administrators Guide for
more information about configuring this type of trunking.
NOTE
This chapter uses the term F_Port trunking to refer to a trunk between the F_Ports on a switch and
the N_Ports on either an Access Gateway module or a Brocade adapter. This type of trunk might be
referred to as N_Port trunking in the Access Gateway Administrator’s Guide or Brocade Adapters
Administrator’s Guide.
Masterless trunking
Masterless trunking means that if the master port goes offline, one of the slave ports automatically
becomes the new master port, 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.
If trunking is not masterless, and if the master port goes offline, traffic disruption can occur
because the slave ports in the trunk group go offline to select the new master port and then come
back online.
Masterless trunking is supported for most platforms and trunking types:
• All F_Port trunking is masterless.
• ISL and ICL trunking is masterless.
• EX_Port trunking is masterless, except for the following:
- Enterprise-class platforms with VF disabled.