Brocade Network Advisor SAN User Manual v11.1x (53-1002167-01, May 2011)

414 Brocade Network Advisor SAN User Manual

53-1002167-01

Virtual Fabrics overview

Terminology

Table 30 lists definitions of Virtual Fabrics terms.

TABLE 30 Virtual Fabrics terms

Term Definition

Physical chassis The physical switch or chassis from which you create logical switches and fabrics.

Logical switch A collection of zero or more ports that act as a single Fibre Channel (FC) switch. When

Virtual Fabrics is enabled on the chassis, there is always at least one logical switch: the

default logical switch. You must assign each logical switch (default or general) in the

same chassis to a different logical fabric. The logical switch supports all E_Ports and

F_Ports. Note that EX_ports are only allowed on the base switch.

Default logical switch A logical switch that is created automatically when the Virtual Fabrics feature is

enabled in a physical chassis. Initially, all ports in a chassis belong to the default logical

switch. The default logical switch always exists as long as Virtual Fabrics is enabled.

You cannot delete the default logical switch. The default logical switch supports all

E_Ports and F_Ports.

Base switch A special logical switch used to communicate among different logical switches. The

legacy EX_port is connected to the base logical switch. Inter-Switch Links (ISLs)

connected to the base switch are used to communicate among different fabrics. The

base switch supports E_Ports and EX_Ports.

Fabric ID (FID) An identifier you assign to a logical switch (default or general) or a base switch to

designate to which logical or base fabric it belongs.

Logical fabric A fabric with at least one logical switch.

Base fabric A fabric formed from base switches that have the same FID. The base fabric provides

the physical connectivity across multiple segments of a fabric over which logical

switches in the fabric can establish logical connectivity.

Extended ISL (XISL) An ISL physically connected between two base switches that carries traffic for multiple

logical fabrics. By default, logical switches are configured to not use XISLs. XISL use is

not supported in the following cases:

• FICON logical fabrics

• Logical switches in an edge fabric connected to an FC router

• Logical switch in InteropMode 2 or InteropMode 3

• Logical switch has VE_Ports and is running Fabric OS 6.4.x or earlier.