52 CHAPTER 2: L OGGING INTO AN ETHERNET S WITCHNote that xxxx is the IP address or the host name of the switch operating as theTelnet server. You can use the ip host to assign a host name to a switch.4 After successful login, the CLI prompt (such as <4210>) appears. If all the VTYuser interfaces of the switch are in use, you will fail to establish the connectionand receive the message that says "All user interfaces are used, please try later!".5 After successfully Telnetting to the switch, you can configure the switch or displaythe information about the switch by executing corresponding commands. You canalso type ? at any time for help.Logging in Using aModemThe administrator can log into the Console port of a remote switch using amodem through public switched telephone network (PSTN) if the remote switch isconnected to the PSTN through a modem to configure and maintain the switchremotely. When a network operates improperly or is inaccessible, you can manageswitches in the network remotely in this way.To log into a switch in this way, you need to configure the administrator side andthe switch properly, as listed in the following table.Configuring the Switch Modem ConfigurationPerform the following configuration on the modem directly connected to theswitch:AT&F ---------------------- Restore the factory settingsATS0=1 ---------------------- Configure to answer automaticallyafter the first ringAT&D ---------------------- Ignore DTR signalAT&K0 ---------------------- Disable flow controlAT&R1 ---------------------- Ignore RTS signalAT&S0 ---------------------- Set DSR to high level by forceATEQ1&W ----------------------- Disable the Modem from returningcommand response and the result, save the changesYou can verify your configuration by executing the AT&V command.n The configuration commands and the output of different modems may differ.Refer to the user manual of the modem when performing the aboveconfiguration.Table 24 Requirements for logging into a switch using a modemItem RequirementAdministratorsideThe PC can communicate with the modem connected to it.The modem is properly connected to PSTN.The telephone number of the switch side is available.Switch side The modem is connected to the Console port of the switch properly.The modem is properly configured.The modem is properly connected to PSTN and a telephone set.The authentication mode and other related settings are configured on theswitch. Refer to Table 13.
