User`s guide

238 Implementing an Open IBM SAN
򐂰 By no means is it possible to have communication over the boundaries of
hard zones. This is also true if malfunctioning fabric initiators try to get around
the name server tables.
򐂰 Hard zones take precedence over all other kinds of zoning (for example, over
broadcast and name server zoning).
򐂰 If no hard zone is enabled at all then all ports are considered as being part of
one large default hard zone.
򐂰 Name server zones and broadcast zones can be implemented within hard
zones. If so, they further limit the connectivity between members of a hard
zone.
򐂰 Hard zones can be created spanning multiple directors in one fabric.
Hard zoning rules
There are a number of rules that must be followed to implement hard zoning
successfully:
򐂰 You can define a maximum of 16 hard zones in an INRANGE fabric,
independently of how many chassis are used in the fabric.
򐂰 When a hard zone is created, it must be in a granularity of four ports.
򐂰 There is a fixed segmentation of a director into port groups which each have
four ports. These port groups will be used when setting up hard zones.
򐂰 A single director port can only be part of just one hard zone. It cannot be a
part of two hard zones at the same time.
򐂰 An all-or-nothing rule applies to hard zoning: Either all director ports are
members of any hard zones, or none of them are members of hard zones.
򐂰 Any update to hard zone layouts will cause all members of affected zones
to perform a fabric login. Hard zone changes should be restricted to initial
setup and at maintenance slots.
Fixed placement of port groups
As mentioned before, the granularity to set up hard zones are groups of four
ports. So one hard zone is built up of one or more multiples of these groups.
The location of these groups is fixed, and you cannot change this. A particular
group consists of four ports: two ports on a FIO blade and two ports with the
same location on a neighboring FIO blade as shown in Figure 3-54.