3Com 1000, User Manual

Page: 55 / 152

Setting Up the Switch Unit 4-11
SDB Ageing Time This field allows you to specify
the ageing time (hours:minutes) for all non-perma-
nent entries in the Switch Database of the unit.
You can set an ageing time in the range 0 minutes
to 277 hours, with a default of 30 minutes. If you
enter 0:00, ageing is turned off. For more informa-
tion about ageing times, refer to
“Setting Up the
Switch Database (SDB)” on page 4-16 .
Spanning Tree Enable / Disable This field allows
you to enable or disable the Spanning Tree Protocol
(STP) on the Switch. For more information about
STP, refer to
“Spanning Tree Protocol” on page
5-12 .
Duplex Mode Half Duplex / Full Duplex on 100M
Ports / Full Duplex on all Ports This field allows you
to set the duplex mode of ports that have Unit
Default specified in the Duplex Mode field of the
Port Setup screen. The default setting is Half Duplex.
For more information about Duplex Mode, refer to
“Setting Up the Switch Ports” on page 4-12 .
Backbone Port 1 / 2 / 3 / ... 24 / 25 / 26
(3C16900A) 1 / 2 / 3 /...12 / 13 / 14 (3C16901A)
If the Bridging Mode field is set to Forward to Back-
bone, and all the ports on the Switch belong to
VLAN 1 and use Port VLAN Mode, then this field
allows you to specify a backbone port for the
Switch. In all other situations, the field is not dis-
played.
On a new or initialized Switch, all ports belong to
VLAN 1 and use Port VLAN Mode.
For more information about VLANs, refer to “Vir-
tual LANs (VLANs)” on page 5-1 . For more informa-
tion about backbone ports and their role in VLAN
functionality, refer to
“Setting Up VLANs on the
Switch” on page 5-8 .
Default RMON Host/Matrix Enable / Disable This
field allows you to enable (start) Hosts and Matrix
RMON sessions on the Default VLAN, or disable
(stop) existing sessions if they are no longer
required. The default setting for this field is Disable.
For more information about RMON sessions, refer to
“RMON” on page 5-22 .
Plug-in Module Type This read-only field displays
the type of Plug-in Module fitted to the rear of the
unit, or displays Not Fitted.
Transceiver Module Type This read-only field
shows the type of Transceiver Module fitted to the
rear of the unit, or displays Not Fitted.
Power Supply Internal / External This read-only
field displays External if the Switch is receiving
power from a Redundant Power System. In all
other cases, this field displays Internal.