FICON Administrator's Guide v6.4.0 (53-1001771-01, June 2010)

8 FICON Administrator’s Guide
53-1001771-01
Access Control in FICON
1
Figure 4 and Figure 5 on page 8 show two cascaded configurations. These configurations require
Channel A to be configured for 2-byte addressing and require IDID and fabric binding. It is
recommended that there be only two domains in a path from a FICON Channel interface to a FICON
Control Unit interface. There are exceptions to the two domain rule when extended fabric solutions
are deployed, for example Brocade 7500 switches between the FICON Directors is allowed.
FIGURE 4 Cascaded configuration, two switches
FIGURE 5 Cascaded configuration, three switches
Access Control in FICON
Zoning is used to control access in a FICON environment. A zone consists of a group of ports or
WWNs. Connectivity is permitted only between connections to the switch that are in the same zone.
There are three types of zoning: WWN, port, and domain,index zoning. A zone configuration
includes at least one zone. In open systems environments and in more complex FICON
deployments, the zone configuration contains multiple zones. Although domain,index zoning is
supported, WWN zoning for QoS is still recommended in environments where NPIV is deployed. For
more information on how to implement QoS D,I zoning in your fabric, refer to the Fabric OS
Administrator’s Guide.
ATTENTION
In FICON environments, only port zoning should be used.
When zoning changes occur, Registered State Change Notification (RSCN) messages are sent out
throughout the zone. RSCNs are part of the low-level Fibre Channel protocol that alerts channels
and devices to changes in the fabric. Using multiple smaller zones instead of one large zone helps
alleviate the need for channels and device interfaces to process RSCNs that are not relevant.
Cascaded Zoning
Figure 6 is typical of multiple sites sharing the same disaster recovery site. Each director at a
remote site—labeled Director 1 and Director 3—can pass traffic to Director 2, but no traffic is
permitted between Zone A and Zone B.
Channel
A
Control
Unit
B
Switch
Domain ID = 21
Switch
Domain ID = 22
Channel
A
Control
Unit
C
Control
Unit
D
Switch
Domain ID = 23
Switch
Domain ID = 21
Switch
Domain ID = 22