EasyManuals Logo

Cisco Catalyst 3650 Hardware Installation Guide

Cisco Catalyst 3650
118 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #90 background imageLoading...
Page #90 background image
5-4
Catalyst 3650 Switch Hardware Installation Guide
OL-29734-01
Chapter 5 Troubleshooting
Diagnosing Problems
Interface Settings
Verify that the port or interface is not disabled or powered off. If a port or interface is manually shut
down on either side of the link, it does not come up until you reenable the interface. Use the show
interfaces privileged EXEC command to see if the interface is error-disabled, disabled, or shut down on
either side of the connection. If needed, reenable the interface.
Ping End Device
Ping from the directly connected switch first, and then work your way back port by port, interface by
interface, trunk by trunk, until you find the source of the connectivity issue. Make sure that each switch
can identify the end device MAC address in its Content-Addressable Memory (CAM) table.
Spanning Tree Loops
STP loops can cause serious performance issues that look like port or interface problems.
A unidirectional link can cause loops. It occurs when the traffic sent by the switch is received by the
neighbor, but the traffic from the neighbor is not received by the switch. A broken cable, other cabling
problems, or a port issue could cause this one-way communication.
You can enable UniDirectional Link Detection (UDLD) on the switch to help identify unidirectional link
problems. For information about enabling UDLD on the switch, see the “Understanding UDLD” section
in the software configuration guide on Cisco.com.
Switch Performance
Speed, Duplex, and Autonegotiation
Port statistics that show a large amount of alignment errors, frame check sequence (FCS), or
late-collisions errors, might mean a speed or duplex mismatch.
A common issue occurs when duplex and speed settings are mismatched between two switches, between
a switch and a router, or between the switch and a workstation or server. Mismatches can happen when
manually setting the speed and duplex or from autonegotiation issues between the two devices.
To maximize switch performance and to ensure a link, follow one of these guidelines when changing the
duplex or the speed settings:
Let both ports autonegotiate both speed and duplex.
Manually set the speed and duplex parameters for the interfaces on both ends of the connection.
If a remote device does not autonegotiate, use the same duplex settings on the two ports. The speed
parameter adjusts itself even if the connected port does not autonegotiate.
Autonegotiation and Network Interface Cards
Problems sometimes occur between the switch and third-party network interface cards (NICs). By
default, the switch ports and interfaces autonegotiate. Laptops or other devices are commonly set to
autonegotiate, yet sometimes issues occur.

Table of Contents

Other manuals for Cisco Catalyst 3650

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the Cisco Catalyst 3650 and is the answer not in the manual?

Cisco Catalyst 3650 Specifications

General IconGeneral
Switching Capacity160 Gbps
Uplink Interfaces4 x 1G SFP or 2 x 10G SFP+
Device TypeSwitch
Form FactorRack-mountable
LayerLayer 3
DRAM4 GB
Flash Memory4 GB
Operating SystemCisco IOS XE
ModelCatalyst 3650
Ports24 or 48 10/100/1000 Ethernet ports
StackingYes
Power over Ethernet (PoE)Yes
Power Supply Options350W AC
VLANs4094

Related product manuals