FW 07.00.00/HAFM SW 08.06.00 McDATA SANpilot User Manual (620-000160-230, April 2005)

Switch Description

1-9

General Information

• Port segmentation - When an ISL activates, the switches

exchange operating parameters to determine if they are

compatible and can join to form a single fabric. If incompatible,

the connecting E_Port at each switch segments to prevent the

creation of a single fabric. A segmented link transmits only Class

F traffic; the link does not transmit Class 2 or Class 3 traffic. The

following conditions cause ports to segment:

— Incompatible operating parameters - Either the resource

allocation time-out value (R_A_TOV) or error-detect time-out

value (E_D_TOV) is inconsistent between switches. To prevent

port segmentation, the same E_D_TOV and R_A_TOV must

be specified for each switch.

— Duplicate domain IDs - One or more domain ID conflicts are

detected.

— Incompatible zoning configurations - zoning configurations

for the switches are not compatible.

— Build fabric protocol error - A protocol error is detected

during the process of forming the fabric.

— No principal switch - No switch in the fabric is capable of

becoming the principal switch.

NOTE: At least one director or switch in a multiswitch fabric must be set to

either principal or default, making it capable of becoming principal switch. If

all directors and switches are set to never principal, all ISLs will segment

(Reason code 05).

— Unresponsive switch - Each switch in a fabric periodically

verifies operation of all attached switches. An ISL segments if

the attached switch does not respond to a verification request.

— ELP retransmission failure timeout - A switch that exhibits a

hardware failure or connectivity problem cannot transmit or

receive Class F frames. The director did not receive a response

to multiple exchange link protocol (ELP) frames, did not

receive a fabric login (FLOGI) frame, and cannot join an

operational fabric.