User guide

Chapter 2 Managing Fabrics 29
Zones
Zoning divides the fabric for purposes of controlling discovery and inbound traffic.
A zone is a named group of ports or devices. Members of the same zone can
communicate with each other and transmit outside the zone, but cannot receive
inbound traffic from outside the zone. A port/device can be a member of up to eight
zones whose combined membership does not exceed 64.
Zoning is hardware enforced on a switch port if the sum of the logged-in devices
plus the devices zoned with devices on that port is 64 or less. If a port exceeds this
sum, that port behaves as a soft zone member. The port continues to behave as a soft
zone member until the sum of logged-in and zoned devices falls back to 64, and the
port is reset.
A zone can be a component of more than one zone set. Several zone sets can be
defined for a fabric, but only one zone set can be active at one time. The active zone
set determines the current fabric zoning.
Membership in a zone can be defined by switch domain ID and port number, device
Fibre Channel address identifier (FCID), or device World Wide Name (WWN).
■ WWN entries define zone membership by the World Wide Name of the attached
device. With this membership method, you can move WWN member devices to
different switch ports in different zones without having to edit the member entry
as you would with a domain ID/port number member. Furthermore, unlike FCID
members, WWN zone members are not affected by changes in the fabric that
could change the Fibre Channel address of an attached device.
■ FCID entries define zone membership by the Fibre Channel address of the
attached device. With this membership method you can replace a device on the
same port without having to edit the member entry as you would with a WWN
member.
■ Domain ID/Port number entries define zone membership by switch domain ID
and port number. All devices attached to the specified port become members of
the zone. The specified port must be an F_Port or an FL_Port.
Aliases
To make it easier to add a group of ports or devices to one or more zones, you can
create an alias. An alias is a named set of ports or devices that are grouped together
for convenience. Unlike zones, aliases impose no communication restrictions
between its members. You can add an alias to one or more zones. However, you
cannot add a zone to an alias, nor can an alias be a member of another alias.