Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
17
No. Problem Action
2 Login is not possible. Perform the following procedure:
1. Make sure that the line vty or ftp-server configuration
command has been set. For details, see the Configuration Guides.
2. Make sure that the terminal you are using has an IP address that is
permitted in the access list for the configuration command line vty
mode. Also, make sure that deny is not specified for the IP address
set in the configuration command access list. For details, see the
Configuration Guides.
3. Make sure that the maximum number of users who can log in has not
been exceeded. For details, see the Configuration Guides.
4. Check whether there is no terminal left and waiting for a login
operation to be completed (that is, a terminal waiting for a user ID or
password to be entered or which has failed to log in).
If there is such a terminal, terminate the communication software at
the terminal.
5. Check whether a connection from a remote terminal to the Switch
was temporarily lost and then restored during a login operation.
If a connection from a remote operation terminal to the Switch has
been lost and then restored when the terminal is being logged in, the
session information will remain in the Switch, which will prevent the
remote operation terminal from newly logging in to the Switch until
the TCP protocol of the session times out and the session is
disconnected. Although the timeout period of the TCP protocol
varies depending on the status of a remote terminal or the network,
the protocol usually times out after 10 minutes.
3 Key entry is not accepted. Perform the following procedure:
1. Data transmission might have been interrupted by XON/XOFF flow
control. End the interruption by pressing Ctrl+Q. If the Switch still
does not accept entry from the keys after this operation, perform
steps 2 and 3.
2. Make sure that the communication software settings are correct.
3. The screen might not be responding because Ctrl+S was pressed.
Press any key.
4 A user remains logged in. Wait until the user is logged out automatically (a maximum of 30 minutes).
If you were editing the configuration, log in to the Switch again and enter
configuration mode to save the configuration, and then finish editing.
3.2.3 Login authentication using RADIUS is not possible
If a login cannot be authenticated by using RADIUS, check the following.
(1) Communication to the RADIUS server
Use the ping operation command if connection from the Switch to the RADIUS server has
been established. If a connection has not been established, see
3.6.1 Communication is
not possible or is disconnected. If an IP address is specified for the VLAN interface in the
configuration, use the
ping operation command from the IP address to make sure that a
connection from the Switch to the RADIUS server has been established.
(2) Settings for the response timeout value and the number of resending
attempts
For RADIUS authentication, depending on the radius-server host, radius-server
retransmit, and radius-server timeout configuration command settings, the maximum
length of time required by the Switch to determine that it is unable to connect to the
RADIUS server is calculated as follows:
set-response-timeout-value (in seconds) × (set-number-of-retry-attempts + 1) ×