Deployment Guide

AD0
AD0 is a system-defined Admin Domain. Unlike user-defined Admin Domains, AD0 has an implicit and
an explicit membership list. User-defined Admin Domains have only an explicit membership list.
• The implicit membership list contains all devices, switch ports, and switches that have not been
assigned to any other Admin Domain.
Initially, the AD0 implicit membership list contains all devices, switch ports, and switches in the fabric.
When you create AD1 through AD254, the devices, switch ports, and switches used to create these
user-defined Admin Domains disappear from the AD0 implicit membership list.
• The explicit membership list contains all devices, switch ports, and switches that you explicitly add to
AD0 and can be used to force device and switch sharing between AD0 and other Admin Domains.
AD0 is managed like any user-defined Admin Domain. The only difference between AD0 and user-
defined Admin Domains is the implicit membership list.
The implicit members of AD0 change dynamically as the membership of other Admin Domains
changes. The explicit members of AD0 are not deleted unless you explicitly remove them.
For example, if DeviceA is not a member of any user-defined Admin Domain, then it is an implicit
member of AD0.
If you explicitly add DeviceA to AD0, then DeviceA is both an implicit and an explicit member of AD0.
• AD0 implicit members: DeviceA
• AD0 explicit members: DeviceA
• AD2 members: None
If you add DeviceA to AD2, then DeviceA is deleted from the AD0 implicit membership list, but is not
deleted from the AD0 explicit membership list.
• AD0 implicit members: None
• AD0 explicit members: DeviceA
• AD2 members: DeviceA
If you then remove DeviceA from AD2, DeviceA is added back to the AD0 implicit membership list
(assuming DeviceA is not in any other Admin Domain).
• AD0 implicit members: DeviceA
• AD0 explicit members: DeviceA
• AD2 members: None
When a new device is added to the fabric, it automatically becomes an implicit member of AD0 until it is
explicitly added to an Admin Domain.
AD0 is useful when you create Admin Domains because you can see which devices, switch ports, and
switches are not yet assigned to any Admin Domains.
AD0 owns the root zone database (legacy zone database).
AD255
AD255 is a system-defined Admin Domain that is used for Admin Domain management. AD255 always
contains all of the devices in the entire physical fabric. You can use AD255 to get an unfiltered view of
the fabric and to view the hierarchical zone databases of AD0 through AD254. All Admin Domain
management is done in the AD255 context.
AD255 does not have a zone database associated with it; you cannot use AD255 to perform any zoning
management tasks (non-read operations such as creating or modifying zones).
AD0
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