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Troubleshooting Notes for the Express 100BASE-TX Switching Hub
TROUBLESHOOTING NOTES FOR THE EXPRESS 100BASE-TX SWITCHING HUB
Troubleshooting Notes from Tech Support for the Express 100BASE-TX
Switching Hub
Connecting to a 10 Mbps segment
The Express Switching Hub is a 100 Mbps-only switch. You can't connect
a 10 Mbps device directly to the switch.
The preferred way to connect the a 10 Mbps segment or device to the
Express Switching Hub is by using the Intel Express 10/100 Downlink to
connect 10 Mbps segments or devices to an Express 100BASE-TX Stackable
Hub or Switching Hub. The Express 10/100 Downlink is a 2 port switch
with each port running at 10 Mbps or 100 Mbps.
Another inexpensive alternative is to using the Express 10/100
Downlink is to connect the segments through a server. Several adapters
on the market (such as the Intel EtherExpress PRO/100 adapter) operate
at either 10 or 100 Mbps. By connecting the Express 100BASE-TX
Stackable Hub to one server adapter at 100 Mbps and your 10BASE-T hub
to a separate adapter at 10 Mbps in the same server, you can route
traffic from the 10 Mbps segment to the 100 Mbps segment through your
Network Operating System (NOS) like Novell NetWare or Windows NT
3.51.
If your NOS doesn't support multi-protocol routing (Windows 95
peer-to-peer and Windows for Workgroups* don't), you must use a Fast
Ethernet switch or router that supports both 10 Mbps and 100 Mbps.
Note: Window NT* 3.51 doesn't include the multi-protocol router
software by default. You can download it from the Microsoft World Wide
Web site.
Straight-through vs. crossover cables
Ports on the switch are wired MDI so you can use a straight-through
cable when connecting to a Fast Ethernet* repeating hub port, which is
usually wired MDI-X. For direct connection to another MDI port
(workstation, server, or another switch), you must use a crossover
cable.
Downloading the Intel MIB (Management Information Base) file
The MIB filename is SWCH1MIB.EXE. You can find the file on Intel's
Customer Support web site (http://www-cs.intel.com) or the Intel BBS
(see the inside back cover of the User Guide for phone numbers).
Note: Be sure you assign an IP configuration to the switch before
using it with an SNMP-compliant network management system (NMS). See
the Quick Start section in the User Guide for more information.
See your NMS documentation for instructions on compiling the MIB for a
new device.
Lost or Forgotten Password
If the password is lost to the Administrative Interface, there is a
back-door which allows the network administrator to log in. Simply
type "debug" at the password prompt, with any user name. Once at the
console prompt, the user must reset the device to its factory defaults
to clear the password using init-nvram.
Troubleshooting the Express Switching Hub
If there is an operating problem with the Express Switching Hub,
incorrect configuration or cabling is probably the cause. Try the
troubleshooting steps below in order:
1. Verify that your cables are wired correctly. This is the most
common problem. Use a UTP crossover cable to directly connect another
switch, server, or workstation to the switch. Use a straight-through
cables when connecting to a repeater. See page 8 for more information.
2. Make sure the unit is plugged into a grounded, functioning AC
outlet providing between 90 VAC and 264 VAC at 50/60 Hz.
3. Review the Link LEDs of other devices to ensure that those ports
you believe should be functioning are properly attached to the switch
with a Category 5 UTP cable.
4. Review the switch's Link LEDS to ensure that ports you believe
should be functioning are properly configured, and not disabled or
partitioned.
5. If you configured a port for full duplex, make sure the device on
the other end is configured for full duplex and is capable of
transmitting in full duplex. Remember, you must have a point-to-point
connection for a full-duplex link. Most repeaters aren't capable of
full duplex.
6. If the FC/FD LED shows excessive activity, see Chapter 1 for
recommendations on dealing with excessive flow control.
7. Make sure that the equipment attached to the switch is properly
configured. If the CLSN LED is on continuously, you may have a problem
with an adapter on the segment.
8. Use the Console Manager to check the switch's status. Use the
sys-stat command to check the overall system status and the
get-port-cfg command to check the status of each port.
The EXPRESS 100BASE-TX SWITCH is a highly reliable unit. If there are
any operating problems, the fault probably lies in some other aspect
of the configuration. However, certain steps may be taken to ensure
that the unit is functioning normally.
The most common problem is a cabling problem. Review all link LED's
to ensure that those ports you believe should be functioning are
properly attached to a cable. It is important to verify that cables
are wired correctly; i.e. use a UTP crossover cable to directly
connect another switch or any other MDI type-device (such as a
workstation) directly to a port.
If a workstation is unable to transmit or receive, review all link
LED's to ensure that those ports you believe should be functioning are
properly configured, and not disabled or partitioned. If the suspect
ports are disabled or do not seem configured properly, re-configure
the port through SNMP management or the Administrative Interface.
Review the port configuration, the Spanning Tree configuration, the
virtual LAN configuration, and any custom filters which may affect the
malfunctioning station. In addition, review all Full Duplex LED's to
ensure that those ports you believe should be functioning are in the
correct mode of operation.
If the Flow Control LED shows excessive activity, or there are
excessive collisions on the network, then the most likely cause is
either poor network configuration, or simply too many devices on the
network. The second case simply requires an upgrade in the network
(adding a switch or, perhaps, a router). The first case is more
difficult to solve, and depends on the traffic patterns. Management
software should be used to isolate the source of the collisions, and
the switch forwarding statistics should be checked to determine which
port(s) are over-flowing.
If the switch has no power, i.e., the LED's do not function, then the
fuse should be checked and replaced with the correct fuse type. The
power specifications for the EXPRESS 100BASE-TX SWITCH are: between 90
VAC and 264 VAC at 50/60 Hz.
Under certain circumstances, it is necessary to reset the
Administrative Interface to the factory defaults. To do this, simply
log in, and type "init-nvram" at the console prompt. Then, type
"warm-reset" to reset the device. The factory defaults will be
reinstalled.
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