3Com 3C17700 - SuperStack 3 Switch 4900, Руководство по началу работы

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28 C
HAPTER
2: I
NSTALLING THE
S
WITCH
WARNING: If you are connecting the Switch to a Type 3 Power Module,
read the Safety Information section in the Type 3 Power Module User
Guide.
CAUTION: The Switch can only use a SuperStack Advanced Redundant
Power System output.
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.
Choosing the Correct
10/100/1000BASE-T
Cables
If your Switch has 10/100/1000BASE-T ports, these ports 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 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
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)
✕ ✓