HP Surestore 64 Director Switch - Manual (Page 128)

112 Configure Operating Parameters
If all directors are set to Principal or Default, the switch with the highest priority and
the lowest WWN becomes the principal switch. Following are some examples of
principal switch selection when directors have these settings:
– If you have three directors and set all to Default, the director with the lowest WWN
becomes the principal switch.
– If you have three directors and set two to Principal and one to Default, the director
with the Principal setting that has the lowest WWN becomes the principal switch.
– If you have three directors and set two to Default and one to Never Principal, the
switch with the Default setting and the lowest WWN becomes the principal switch.
Note that at least one director in a multiswitch fabric needs to be set as Principal or
Default. If all of the directors are set to Never Principal, all of the interswitch links
(ISLs) will segment. If all but one switch is set to Never Principal and the director that
was principal goes offline, then all of the other ISLs will segment.
Note We recommend you leave the switch priority setting as Default. If you are
considering setting this value to something other than default, refer to the
section on principal switch selection for multiswitch fabrics in the hp surestore
director fc-64 Planning Guide (HP A6534-90903) for details.
In the audit log, you may notice that the Principal setting maps to a number code of 1,
Default maps to a number code of 254, and Never Principal maps to a number code of
255. The number codes of 2 - 253 are not currently in use.
• Rerouting Delay
Placing a check mark in the check box to the left of the Rerouting Delay option enables
rerouting delay. This option is only applicable if the configured director 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