Reference Guide

3. Enter y to disable the Topology Discovery feature.
NOTE
Topology discovery is disabled by default.
ATTENTION
Disabling discovery of management server topology might erase all node ID entries.
Example of disabling discovery
The following example shows what happens when you disable topology discovery.
switch:admin> mstddisable
This may erase all NID entries. Are you sure? (yes, y, no, n): [no] y
Request to disable MS Topology Discovery Service in progress....
*MS Topology Discovery disabled locally.
switch:admin> mstddisable all
This may erase all NID entries. Are you sure? (yes, y, no, n): [no] y
Request to disable MS Topology Discovery Service in progress....
*MS Topology Discovery disabled locally.
*MS Topology Discovery Disable Operation Complete!!
Device login
A device can be storage, a host, or a switch. When new devices are introduced into the fabric, they must be powered on and, if a host or
storage device, connected to a switch. Switch-to-switch logins (using the E_Port) are handled differently than storage and host logins.
E_Ports exchange different frames than the ones listed below with the Fabric Controller to access the fabric. Once storage and host
devices are powered on and connected, the following logins occur:
1. FLOGI — Fabric Login command establishes a 24-bit address for the device logging in, and establishes buffer-to-buffer
credits and the class of service supported.
2. PLOGI — Port Login command logs the device into the name server to register its information and query for devices that share
its zone. During the PLOGI process, information is exchanged between the new device and the fabric. Some of the following
types of information exchanges occur:
∙ SCR — State Change Registration registers the device for State Change Notifications. If a change in the fabric occurs, such
as a zoning change or a change in the state of a device to which this device has access, the device receives a Registered
State Change Notification (RSCN).
∙ Registration — A device exchanges registration information with the name server.
∙ Query — Devices query the name server for information about the device it can access.
Principal switch
In a fabric with multiple switches, and one inter-switch link (ISL) exists between any two switches, a principal switch is automatically
elected. The principal switch provides the following capabilities:
∙ Maintains time for the entire fabric. Subordinate switches synchronize their time with the principal switch. Changes to the clock
server value on the principal switch are propagated to all switches in the fabric.
∙ Manages domain ID assignment within the fabric. If a switch requests a domain ID that has been used before, the principal
switch grants the same domain ID unless it is in use by another switch.
Understanding Fibre Channel Services
Brocade Fabric OS Administration Guide, 8.0.1
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