M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D EMagnum6K25# userMagnum6K25(user)## useraccess user=peter service=telnet enableTelnet Access Enabled.Magnum6K25(user)## exitMagnum6K25# show sessionCurrent Sessions:SL # Session Id Connection User Name User Mode1 1 163.10.10.14 manager Manager2 2 163.11.11.15 peter Manager3 3 163.12.12.16 operator OperatorMagnum6K25# kill session id=3Session Terminated.Magnum6K25#FIGURE 27 – managing and viewing multiple telnet sessionsIn the above example, the user with user-id peter is given telnet access (which was disabled earlier inChapter 2). Then multiple users telnet into the switch. This is shown using the “show session”command. The user operator session is then terminated using the “kill session” command.The default port – port 23 is used for telnet.A maximum of four simultaneous telnet sessions are allowed at any time on theswitch. The commands in these telnet windows are executed in a round robin – i.e.if one window takes a long time to finish a command, the other windows mayencounter a delay before the command is completed. For example, if one windowis executing a file download, the other windows will not be able to execute thecommand before the file transfer is completed. Another example, if a outboundtelnet session is started from the switch (through a telnet window) then the otherwindows will not be able to execute a command till the telnet session is completed.Using SSHSSH is available in MNS-6K-SECURE.The Telnet, rlogin, rcp, rsh commands have a number of security weakness: allcommunications are in clear text and no machine authentication takes place. Thesecommands are open to eavesdropping and tcp/ip address spoofing. Secure Shell orSSH is a network protocol that allows data to be exchanged over a secure channelbetween two computers. SSH uses public/private key RSA authentication to checkthe identity of communicating peer machines, encryption of all data exchanged (with44
