Ports - Cisco Catalyst 3750 Hardware Installation Manual

Chapter 2 Product Overview
Note

10/100/1000 Ports

Note
Note
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For information about Cisco IP Phones and Cisco Aironet Access Points, refer to
the documentation that came with your IP phone or access point.
Many legacy powered devices, including older Cisco IP phones and access points
that do not fully support IEEE 802.3af, might not support PoE when connected to
the switches by a crossover cable.
You can set the 10/100/1000 ports to operate in 10, 100, or 1000 Mbps in full
duplex. You can also set these ports for speed and duplex autonegotiation in
compliance with IEEE 802.3ab. (The default setting is autonegotiate.) When set
for autonegotiation, the port senses the speed and duplex settings of the attached
device and advertises its own capabilities. If the connected device also supports
autonegotiation, the switch port negotiates the best connection (that is, the fastest
line speed that both devices support and full-duplex transmission if the attached
device supports it) and configures itself accordingly. In all cases, the attached
device must be within 328 feet (100 meters).
You can configure duplex mode to half, full, or autonegotiate on Gigabit Ethernet
interfaces if the speed is set to 10 or 100 Mbps. You cannot configure half-duplex
mode on Gigabit Ethernet interfaces if the interface speed is 1000 Mbps.
100BASE-TX and 1000BASE-T traffic requires Category 5 cable. 10BASE-T
traffic can use Category 3 or Category 4 cables.
When connecting the switch to workstations, servers, routers, and Cisco IP
Phones, be sure that the cable is a straight-through cable. When connecting the
switch to switches or hubs, use a crossover cable. When using a straight-through
or crossover cable for 1000BASE-T connections, be sure to use a twisted
four-pair, Category 5 cable for proper operation. Pinouts for the cables are
described in Appendix B, "Connector and Cable Specifications."
Catalyst 3750 Switch Hardware Installation Guide
Front Panel Description
2-11