3Com 3CR17561-91-US - Switch 4500 26PORT Managed 24 10/100 2 Gbe Stackable..., Руководство по началу работы, Страница: 36 / 128

36 C
HAPTER
2: I
NSTALLING THE
S
WITCH
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 13.
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 13 Cables required to connect the Switch to other devices if
auto-negotiation is disabled
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
connector located, for example, on a Switch rack or patch panel. The
RJ-45 connector is now a grounded port.
WARNING: The Switch 4500 PWR supports Power over Ethernet on
10/100 ports only. These ports should only be used for Ethernet wiring
within the same building.
Cross-over Cable Straight-through Cable
Switch to Switch
(MDIX to MDIX)
✓ ✕
Switch to Hub
(MDIX to MDIX)
✓ ✕
Switch to PC (NIC)
(MDIX to MDI)
✕ ✓