[Day 6] 4. Telnetting

Telnet Between Routers:

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  A#telnet 172.16.20.2

  : This command will telnet from Router A to Router B.
• Once connected to Router B:
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    B> enable

    : Switch to privileged EXEC mode on Router B.
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    B#telnet 172.16.40.2

    : This will telnet from Router B to Router C.
• Once connected to Router C:
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    C> enable

    : Switch to privileged EXEC mode on Router C.

Note: In a single CLI window, you can have multiple active telnet sessions (e.g., from Router A to Router B, and then from Router B to Router C). Technically, three separate telnet sessions are running.

Managing Multiple Telnet Sessions:

• Switching Between Telnet Sessions:
  Use

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  Shift + Ctrl + 6

  , then press
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  x

  . This will return you to the previous router without closing the current telnet session.

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  C#show sessions

  :
  Displays all active telnet sessions. The current session will be marked with an asterisk (*).

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  C#1

  :
  This command lets you switch to session 1 from any other session. If you are currently in session 2, this command will take you back to session 1.

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  C#disconnect 2

  :
  Disconnects session number 2.

Managing Users and Lines:

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  C#show users

  :
  Displays a list of users currently logged into the router.

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  C#clear line 1

  :
  Disconnects a user on line 1 (e.g., another administrator using telnet).

Telnet Limitations:

• Simultaneous Telnet Connections:
  Up to 7 administrators can telnet into a Cisco router simultaneously.

Telnet Shortcut:

• You can simply type the IP address (e.g.,
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  A# 172.16.20.2

  ) to initiate a telnet session by default because the router assumes telnet unless otherwise specified.