Users Guide

Name Server
Each participant in the FC environment has a unique ID, which is called the World Wide Name (WWN). This
WWN is a 64-bit address.
A Fibre Channel fabric uses another addressing scheme to address the ports in the switched fabric. Each port
in the switched fabric is assigned a 24-bit address by the FC switch. When the device logs into the switch
fabric on a specific port with its WWN, the switch assigns the port address to that port, and the switch also
maintains the correlation between the port address and the WWN address of the device on that port. This
function of the switch is implemented by using a name server, a database of objects in which the fabric
attached device registers its values.
FC-ID: 24-bit port address. Consists of three parts:
• Domain: Address of the switch itself. There are only 239 addresses available for switches in your SAN
environment. The domain number allows each switch to have a unique identifier if you have multiple
interconnected switches in your environment.
• Area: Identifies a group of F_Ports. Each group of ports has a different area number, even if there is only
one port in the group.
• Port: Provides 256 addresses for identifying attached N_Ports and NL_Ports.
The following sequence explains the operation for the attached N_Port:
• N_Port sends a Fabric Login (FLOGI) as it requests a unique 24-bit address from the Fabric Login Server.
• N_Port sends FLOGI to address 0xFFFFFE. Upon success, it obtains a valid address (FCID).
• N_Port sends a Port Login (PLOGI) to inform the Fabric Name Server of its personality and capabilities,
this includes WWNN, WWPN.
• N_Port sends PLOGI to address 0xFFFFFC to register this address with the name server.
Command Description
show fc ns
switch
Display all the devices in name server database of the switch.
show fc ns
switch brief
Displays the local name server entries — brief version.
show fc ns
fabric
Display all the devices in name server database of the fabric.
show fc ns
fabric
Displays the fabric name server entries — brief version.
show fc
topology
Displays the topology information of the local switch.
The following configurations are applicable only after configuring the switch mode to fabric services using
the fc switch-mode fabric-services command. When you set Switch mode to Fabric Services, the
Fibre Channel interfaces are set to shutdown and the fcoe-map default_full_fabric applies. Any
previously configured fcoe-map is removed and you cannot remove the fcoe-map
default_full_fabric
from the Fibre Channel interfaces.
Fabric Services 378