Choosing The Correct 10/100/1000 Cables - 3Com 4070 Getting Started Manual

Choosing the Correct
10/100/1000 Cables
If there is evidence of a problem, see
LEDs" on page 56 for a list of suggested solutions.
CAUTION: The Switch has no ON/OFF switch; the only method of
connecting or disconnecting mains power is by connecting or
disconnecting the power cord.
The 10/100/1000 ports on the front of the Switch 4050 and Switch 4060
are Auto-MDIX, that is they have a cross-over capability. These ports can
automatically detect whether to operate in MDI or MDIX mode. Therefore
you can make a connection to one of the ports with a straight-through
(MDI) or a cross-over cable (MDIX).
The Auto-MDIX feature only operates when auto-negotiation is enabled.
If auto-negotiation is disabled, all the Switch ports are configured as
MDIX (cross-over). If you want to make a connection to another MDIX
port, you need a cross-over cable. Many ports on workstations and
servers are configured as MDI (straight-through). If you want to make a
connection to an MDI port, you need to use a standard straight-through
cable. See Table 7.
3Com recommends that you use at least Category 5 twisted pair cable —
the maximum segment length for this type of cable is 100 m (328 ft).
Table 7 Cables required to connect the Switch 4050/4060 to other devices if
auto-negotiation is disabled
Switch to Switch
(MDIX to MDIX)
Switch to Hub
(MDIX to MDIX)
Switch to PC (NIC)
(MDIX to MDI)
CAUTION: If you want to install the Switch using a Category 5E or
Category 6 cable, 3Com recommends that you briefly connect the cable
to a grounded port before connecting network equipment. If you do not,
the cable's Electrostatic Discharge (ESD) may damage the Switch's port.
You can create a grounded port by connecting all wires at one end of a
UTP cable to an earth ground point, and the other end to a female RJ-45
"Solving Problems Indicated by
Cross-over Cable
The Power-up Sequence
Straight-through Cable
29