director 2/64 installation guide

director 2/64 installation guide 1–5
Overview
CAUTION: If zoning is implemented by port number, a change to the director
fiber-optic cable configuration disrupts zone operation and may incorrectly include or
exclude a device from a zone.
If zoning is implemented by WWN, removal and replacement of a device HBA or Fibre
Channel interface (thereby changing the device WWN) disrupts zone operation and
may incorrectly include or exclude a device from a zone.
In Open Fabric mode, only zoning by WWN is supported. Zoning by port numbers is
not.
Zones are grouped into zone sets. A zone set is a group of zones that is enabled
(activated) or disabled across all directors and edge switches in a multi-switch fabric.
Only one zone set can be enabled at one time.
Multi-Switch Fabrics
A Fibre Channel topology that consists of one or more interconnected directors or
switch elements is called a fabric. Operational software provides the ability to
interconnect directors (through expansion port (E_Port) connections) to form a
multi-switch fabric. The data transmission path through the fabric is typically
determined by fabric elements and is user-transparent. Subject to zoning restrictions,
devices attached to any interconnected director can communicate with each other
through the fabric.
Because a multi-switch fabric is typically complex, maintenance personnel should be
aware that several factors can degrade fabric performance or cause connectivity
failures. These factors include:
• Domain ID assignment—Each director in a fabric is identified by a unique
domain ID that ranges from 1 through 31. A domain ID of 0 is invalid. If two
operational fabrics join, they determine if any domain ID conflicts exist between
the fabrics. If one or more conflicts exist, the E_Ports that form the interswitch
link (ISL) segment to prevent the fabrics from joining.
• Zoning—In a multi-switch fabric, zoning is configured on a fabric-wide basis,
and a change to the zoning configuration is applied to all directors and switch
elements in the fabric. To ensure zoning is consistent across a fabric, the following
rules are enforced when two fabrics (zoned or unzoned) join:
— Fabric A unzoned and Fabric B unzoned—The fabrics join successfully,
and the resulting fabric remains unzoned.
— Fabric A zoned and Fabric B unzoned—The fabrics join successfully, and
fabric B automatically inherits the zoning configuration from fabric A.