The Autozone feature is a mechanism to automate zoning of devices. This feature can be used to reduce the administrative overhead of manually creating and updating the switch zone configuration each time a device is added to the SAN to a one-time command. An administrator has to configure the Autozone feature after the initial deployment […]
Zoning can be enforced in two ways: soft and hard. Each end device (N port) discovers other devices in the fabric by querying the name server. When a device logs in to the name server, the name server returns the list of other devices that can be accessed by the querying device. If an N […]
SAN port channels refer to the aggregation of multiple physical interfaces into one logical interface to provide higher aggregated bandwidth, load balancing, and link redundancy. Port channels can connect to interfaces across switching modules, so a failure of a switching module cannot bring down the port channel link. In Figure 8-28, port channel A aggregates […]
Port VSAN membership on the switch is assigned on a port-by-port basis. By default, each port belongs to the default VSAN. You can assign VSANs to ports either statically or dynamically. To assign dynamic VSAN membership to ports, you assign VSANs based on the device WWN. This method is referred to as Dynamic Port VSAN […]
A VSAN is a virtual storage-area network (SAN). VSANs provide isolation among devices that are physically connected to the same fabric. With VSANs, you can create multiple logical SANs over a common physical infrastructure. Each VSAN is a logically and functionally separate SAN with its own set of Fibre Channel fabric services. This partitioning of […]
An application keeps the configuration synchronized in a fabric through CFS. Two such fabrics might merge as a result of an ISL coming up between them. These two fabrics could have two different sets of configuration information that need to be reconciled in the event of a merge. CFS provides notification each time an application […]
When you configure (first-time configuration) a Cisco NX-OS feature (or application) that uses the CFS infrastructure, that feature starts a CFS session and locks the fabric. When a fabric is locked, the Cisco NX-OS software does not allow any configuration changes from a switch to this Cisco NX-OS feature, other than the switch holding the […]
In the Ethernet world, an ARP table maintains a database for resolution between the MAC address (Layer 2) and IP address (Layer 3). Similarly, in the Fibre Channel world, every switch maintains an FLOGI and an FCNS database that maintains the resolution between WWNs (Layer 2) and FCIDs (Layer 3). The FLOGI database logs every […]
Domain IDs uniquely identify a switch in a VSAN. A switch may have different domain IDs in different VSANs. The domain ID is part of the overall FCID. The configured domain ID can be preferred or static. When you assign a static domain ID type, you are requesting a particular domain ID. If the switch […]
Buffer-to-buffer credits (BB_credits) are a flow control mechanism to ensure that FC switches do not run out of buffers because switches must not drop frames. BB_credits are negotiated on a per-hop basis between ports when the link is brought up. When the transmitter sends a port login request, the receiver responds with an accept (ACC) […]
