3Com 3CR17251-91 - Switch 5500G-EI Stackable Gigabit..., Getting Started Manual, Page: 74 / 148

74 C
HAPTER
4: C
REATING AN
XRN S
TACKING
F
ABRIC
Guidelines For
Interconnecting
Units
This section offers some guidelines for creating a Fabric. Using these
guidelines will help prevent problems arising when setting up your Fabric.
■
The maximum number of Switch units that can be interconnected is
eight.
■
It is not possible to create a Fabric by interconnecting a 3Com Switch
5500 with any other 3Com device (such as a 5500G-EI) or mix
Enhanced Image (EI) Switch 5500 units with Standard Image (SI) units.
■
3Com strongly recommends that you upgrade all Switches to be
interconnected to the latest software agent.
■
3Com recommends that you remove the configuration file from a
Switch unit that has previously been used elsewhere in your network
before you interconnect to an existing unit. If you do not do this,
problems may be caused by conflicting Switch configurations. Use the
dir
command from the User View to display the configuration files
stored on the Switch and locate the
[ filename ].cfg
file. Do NOT
under any circumstances remove the
3comoscfg.def
file (this is the
default configuration file).
For a detailed description of how XRN Technology operates and
implementation guidelines, please refer to the Configuration Guide on
the CD-ROM that accompanies your Switch.
Unit Numbering
within the Fabric
When a Fabric is created using the Switch 5500 the unit numbering can
be determined in two ways.
■
You can manually assign unit IDs 1 to 8 to specific units using the
c
hange[self-unit, unit-id] to [1-8,
auto-numbering]
command from the System View. If you
manually assign unit IDs to a Switch via the
change
command the IDs
will be retained after a power cycle.
If you add a unit to a Fabric that has previously been manually
configured with a unit ID and this conflicts with an ID already within
the Fabric, then the Switch with the lowest MAC address assumes the
ID in question and the other unit will automatically renumber.
3Com recommends that you manually assign the unit IDs within the
Fabric if you wish to have predictability of knowing which units have
which IDs at all times.
■
Fabric topology is ‘discovered’ and the units auto-number their IDs.