3Com 3CRUS2475 - Page 516

516 CHAPTER 37: TROUBLESHOOTING
■ No connection and the port LED is off
■ Add and Edit pages do not open.
■ Lost password
Problem Possible Cause Solution
Cannot connect to
management using
RS-232 serial connection
Ensure the terminal
emulator program is set
to
VT-100 compatible,
9600 baud rate, no
parity, 8 data bits and
one stop bit.
Use the included cable,
or ensure that the
pin-out complies with a
standard null-modem
cable.
Cannot connect to
switch management
using Telnet, HTTP,
SNMP, etc.
Ensure that the switch
has a valid IP address,
subnet mask and a
configured default
gateway.
Check that your cable is
properly connected with
a valid link light, and that
the port has not been
disabled.
Ensure that your
management station is
plugged into the
appropriate VLAN to
manage the device.
If you cannot connect
using Telnet or the web,
the maximum number of
connections may already
be open. Please try again
at a later time.
No response from the
terminal emulation
software
Faulty serial cable Replace the serial cable.
Incorrect serial cable Replace the serial cable
for a pin-to-pin
straight/flat cable.