Cisco Catalyst 3750 Hardware Installation Guide

Chapter 4 Troubleshooting
Diagnosing Problems
4-6
Catalyst 3750 Switch Hardware Installation Guide
78-15136-03
No connectivity Incorrect or bad cable
These are results of no link at both
ends:
• A crossover cable was used
when a straight-through was
required, or vice-versa.
• The cable is wired incorrectly.
• A crossover or straight-through
cable is wired incorrectly.
• STP checking for possible
loops.
• For the correct pinouts and
the proper application of
crossover vs.
straight-through cables, see
the “Two Twisted-Pair
Cable Pinouts” section on
page B-5.
• Enable the automatic
medium-dependent-
interface crossover
(Auto-MDIX) feature.
Note 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.
• Replace with a tested good
cable.
• For 1000BASE-T
connections, be sure to use
a twisted four-pair,
Category 5 cable.
• Wait 30 seconds for the port
LED to turn green.
Table 4-1 Common Problems and Solutions (continued)
Symptom Possible Cause Resolution

Cisco Catalyst 3750 Specifications

General

Device Type	Switch
Switching Capacity	32 Gbps
Forwarding Rate	38.7 Mpps
Stacking Bandwidth	32 Gbps
RAM	128 MB
Jumbo Frame Support	Yes
Switch Type	Managed
Model	Catalyst 3750 Series
Uplink Interfaces	SFP
Form Factor	Rack-mountable
MAC Address Table Size	12, 000 entries
Routing Protocol	RIP, OSPF, EIGRP
Remote Management Protocol	SNMP, Telnet, HTTP
Features	Layer 3 switching, Layer 2 switching, auto-negotiation, BOOTP support, ARP support, VLAN support, auto-uplink (auto MDI/MDI-X), IGMP snooping, traffic shaping, MAC address filtering, Quality of Service (QoS), Jumbo Frames support, MLD snooping, Dynamic ARP Inspection (DAI), Cisco EnergyWise technology
Power over Ethernet (PoE)	PoE
Operating Temperature	-5 - 45 °C
Operating Humidity	10% to 85% non-condensing