After using Telnet to log in to a device, you can view information about the current user interface, every user interface, and established TCP connections.
Prerequisites
Telnet login has been configured.
Procedure
- Run the display users [ all ] command to check information about user interfaces.
- Run the display tcp status command to check established TCP connections.
- Run the display telnet server status command to check the status and configurations of the Telnet server.
- After configuring whitelist session-CAR for Telnet, you can verify the configuration.
- For IPv4, run the display cpu-defend whitelist session-car telnet statistics slot slot-id command to check statistics about whitelist session-CAR for Telnet on a specified interface board.
To view new statistics, run the reset cpu-defend whitelist session-car telnet statistics slot slot-id command to clear the existing statistics about whitelist session-CAR for Telnet on a specified interface board, and then run the display cpu-defend whitelist session-car telnet statistics slot slot-id command.
- For IPv6, run the display cpu-defend whitelist-v6 session-car telnetv6 statistics slot slot-id command to check statistics about whitelist session-CAR for Telnet on a specified interface board.
To view new statistics, run the reset cpu-defend whitelist-v6 session-car telnetv6 statistics slot slot-id command to clear the existing statistics about whitelist session-CAR for Telnet on a specified interface board, and then run the display cpu-defend whitelist-v6 session-car telnetv6 statistics slot slot-id command.
- Run the display vty ip-block all command to check all IP addresses that fail to be authenticated.
- Run the display vty ip-block list command to check the list of IP addresses that are blocked due to authentication failures.