HP Cisco Nexus 5000 Cisco Nexus 5000 Series Switch CLI Software Configuration - Page 546

Device Alias Databases Chapter 39 Distributing Device Alias Services Send feedback to [email protected] Device Alias Modes You can specify that aliases operate in basic or enhanced modes. When operating in basic mode, which is the default mode, the device alias is immediately expanded to a pWWN. In basic mode, when device aliases are changed to point to a new HBA, for example, that change is not reflected in the zone server. Users must remove the previous HBA's pWWN, add the new HBA's pWWN, and then reactivate the zoneset. When operating in enhanced mode, applications accept a device alias name in its "native" format. Instead of expanding the device alias to a pWWN, the device alias name is stored in the configuration and distributed in its native device alias format. So applications such as zone server, PSM or DPVM can automatically keep track of the device alias membership changes and enforce them accordingly. The primary benefit of operating in enhanced mode is that you have a single point of change. Whenever you change device alias modes, the change is distributed to other switches in the network only if device alias distribution is enabled or on. Otherwise, the mode change only takes place on the local switch. Note Enhanced mode, or native device alias-based configurations are not accepted in interop mode VSANs. IVR zoneset activation will fail in interop mode VSANs if the corresponding zones have native device alias-based members. Changing Device Alias Mode Guidelines When changing device alias modes, follow these guidelines: • If two fabrics running in different device alias modes are joined together, the device alias merge will fail. There is no automatic conversion to one mode or the other during the merge process. In this situation, you must to select one mode over the other. • Before changing from enhanced to basic mode, you must first explicitly remove all native device alias-based configurations from both local and remote switches, or, replace all device alias-based configuration members with the corresponding pWWN. • If you remove a device alias from the device alias database, all applications will automatically stop enforcing the corresponding device alias. If that corresponding device alias is part of an active zoneset, all the traffic to and from that pWWN is disrupted. • Renaming the device alias not only changes the device alias name in the device alias database, but also replaces the corresponding device alias configuration in all the applications. • When a new device alias is added to the device alias database, and the application configuration is present on that device alias, it automatically takes effect. For example, if the corresponding device alias is part of the active zoneset and the device is online, then zoning is enforced automatically. You do not have to reactivate the zoneset. • If a device alias name is mapped to a new HBA's pWWN, then the application's enforcement changes accordingly. In this case, the zone server automatically enforces zoning based on the new HBA's pWWN. 39-4 Cisco Nexus 5000 Series Switch CLI Software Configuration Guide OL-16597-01