EMC Connectrix DS-32M2, User Manual

Page: 120 / 356

5
5-10 Connectrix DS-32M2 User Guide
Configuring the Switch
◆
If no director/switch is set to Principal but one or more are set to
Default
, the director/switch with the lowest WWN number
among those set to Default becomes the principal switch.
The Switch Priority setting for every other switch/director
remains unchanged.
◆
If all directors/switches are set to Never Principal, no
director/switch can be principal. In this case, all of the ISLs will
segment, with reason code 05 (no switch is capable of becoming a
principal switch).
If all but one director/switch in the fabric is set to Never Principal,
and the principal switch goes off line, all remaining ISLs will
segment, with reason code 05.
If the principal switch was selected by WWN, adding a switch with a
lower WWN does not change the principal if the newly added switch
is set to Open Fabric 1.0 Interop Mode. (Refer to Configuring the
Operating Mode on page 5-4.) This is because adding such a switch
does not cause a Build Fabric process. The next time a Build Fabric
occurs, however, the switch with the lowest WWN will become
principal.
In some logs, Switch Priority settings map to numbers: Principal = 1,
Default
= 254, Never Principal = 255.
Rerouting Delay
Placing a check mark in the check box to the left of the Rerouting
Delay
option enables rerouting delay. This option is applicable only if
the switch is in a multiswitch fabric. The default state is disabled.
Enabling the rerouting delay ensures that frames are delivered in
order through the fabric to their destination. If there is a change to the
fabric topology that creates a new path (for example, a new switch is
added to the fabric), frames may be routed over this new path if its
hop count is less than a previous path with a minimum hop count.
This may result in frames being delivered to a destination out of
order since frames sent over the new, shorter path may arrive ahead
of older frames still in route over the older path.
If the rerouting delay is enabled, traffic ceases in the fabric for the
time specified for E_D_TOV. This delay allows frames sent on the old
path to exit to their destination before new frames begin traversing
the new path.