The Fabric Configuration Server (FCS) provides discovery of topology attributes and maintains a repository of configuration information of fabric elements. A management application is usually connected to the FCS on the switch through an N port. The FCS views the entire fabric based on the following objects:
Interconnect element (IE) object—Each switch in the fabric corresponds to an IE object. One or more IE objects form a fabric.
Port object—Each physical port in an IE corresponds to a port object. This includes the switch ports (xE and F ports) and their attached N ports.
Platform object—A set of nodes may be defined as a platform object to make it a single manageable entity. These nodes are end-devices (host systems, storage subsystems) attached to the fabric. Platform objects reside at the edge switches of the fabric.
Each object has its own set of attributes and values. A null value may also be defined for some attributes.
In the Cisco Nexus device environment, a fabric may consist of multiple VSANs. One instance of the FCS is present per VSAN.
FCS supports the discovery of virtual devices. The fcs virtual-device-add command, entered in FCS configuration submode, allows you to discover virtual devices in a particular VSAN or in all VSANs.
If you have attached a management application to a switch, all the frames directed towards the FCS in the switch are part of the port VSAN in the switch port (F port). Your view of the management application is limited only to this VSAN. However, information about other VSANs that this switch is part of can be obtained either through the SNMP or CLI.
In the following figure, Management Application 1 (M1) is connected through an F port with port VSAN ID 1, and Management Application 2 (M2) is connected through an F port with port VSAN ID 2. M1 can query the FCS information of switches S1 and S3, and M2 can query switches S3 and S4. Switch S2 information is not known to both of them. FCS operations can be done only on those switches that are visible in the VSAN. M2 can send FCS requests only for VSAN 2 even though S3 is also a part of VSAN 1.
Figure 1. FCSs in a VSAN Environment