B-1

Appendix B: Troubleshooting

Problems Accessing the Management Interface

Table B-1 Troubleshooting Chart
Symptom Action
Cannot connect using Telnet,
web browser, or SNMP
software
Be sure the switch is powered up.
Check network cabling between the management station and the switch.
Check that you have a valid network connection to the switch and that the
port you are using has not been disabled.
Be sure you have configured the VLAN interface through which the
management station is connected with a valid IP address, subnet mask
and default gateway.
Be sure the management station has an IP address in the same subnet as
the switch’s IP interface to which it is connected.
If you are trying to connect to the switch via the IP address for a tagged
VLAN group, your management station, and the ports connecting
intermediate switches in the network, must be configured with the
appropriate tag.
If you cannot connect using Telnet, you may have exceeded the maximum
number of concurrent Telnet/SSH sessions permitted. Try connecting
again at a later time.
Cannot connect using
Secure Shell
If you cannot connect using SSH, you may have exceeded the maximum
number of concurrent Telnet/SSH sessions permitted. Try connecting
again at a later time.
Be sure the control parameters for the SSH server are properly configured
on the switch, and that the SSH client software is properly configured on
the management station.
Be sure you have generated a public key on the switch, and exported this
key to the SSH client.
Be sure you have set up an account on the switch for each SSH user,
including user name, authentication level, and password.
Be sure you have imported the client’s public key to the switch (if public
key authentication is used).
Cannot access the on-board
configuration program via a
serial port connection
Be sure you have set the terminal emulator program to VT100 compatible,
8 data bits, 1 stop bit, no parity, and the baud rate set to any of the
following (9600, 19200, 38400, 57600, 115200 bps).
Check that the null-modem serial cable conforms to the pin-out
connections provided in the Installation Guide.
Forgot or lost the password Contact your local distributor.