3-3Authentication mode Telnet configuration DescriptionPerform commonconfigurationPerform common TelnetconfigurationOptionalRefer to Table 3-2.To improve security and prevent attacks to the unused Sockets, TCP 23 and TCP 22, ports for Telnetand SSH services respectively, will be enabled or disabled after corresponding configurations.z If the authentication mode is none, TCP 23 will be enabled, and TCP 22 will be disabled.z If the authentication mode is password, and the corresponding password has been set, TCP 23will be enabled, and TCP 22 will be disabled.z If the authentication mode is scheme, there are three scenarios: when the supported protocol isspecified as telnet, TCP 23 will be enabled; when the supported protocol is specified as ssh, TCP22 will be enabled; when the supported protocol is specified as all, both the TCP 23 and TCP 22port will be enabled.Telnet Configuration with Authentication Mode Being NoneConfiguration ProcedureFollow these steps to configure Telnet with the authentication mode being none:To do… Use the command… RemarksEnter system view system-view —Enter one or more VTY userinterface viewsuser-interface vty first-number[ last-number ] —Configure not to authenticate userslogging in to VTY user interfaces authentication-mode noneRequiredBy default, VTY users areauthenticated after logging in.Configure the command levelavailable to users logging in to VTYuser interfaceuser privilege level levelOptionalBy default, commands of level 0 areavailable to users logging in to VTYuser interfaces.Configure the protocols to besupported by the VTY userinterfaceprotocol inbound { all | ssh |telnet }OptionalBy default, both Telnet protocol andSSH protocol are supported.Set the commands to be executedautomatically after a user login tothe user interface successfullyauto-execute command textOptionalBy default, no command is executedautomatically after a user logs into theVTY user interface.Make terminal services available shellOptionalBy default, terminal services areavailable in all user interfaces.
