Learning by Doing: CISCO Certified Network ... - SCN Research

william#debug telnet
Incoming Telnet debugging is on
00:36:59: Telnet66: 1 1 251 1
00:36:59: TCP66: Telnet sent WILL ECHO (1)
00:36:59: Telnet66: 2 2 251 3
00:36:59: TCP66: Telnet sent WILL SUPPRESS-GA (3)
00:36:59: Telnet66: 80000 80000 253 24
00:36:59: TCP66: Telnet sent DO TTY-TYPE (24)
00:36:59: Telnet66: 10000000 10000000 253 31
00:36:59: TCP66: Telnet sent DO WINDOW-SIZE (31)
00:36:59: TCP66: Telnet received DO SUPPRESS-GA (3)
00:36:59: TCP66: Telnet received WILL TTY-SPEED (32) (refused)
00:36:59: TCP66: Telnet sent DONT TTY-SPEED (32)
00:36:59: TCP66: Telnet received WILL WINDOW-SIZE (31)
00:36:59: TCP66: Telnet received WILL LOCAL-FLOW (33)
00:36:59: TCP66: Telnet sent DO LOCAL-FLOW (33)
00:36:59: Telnet66: Sent SB 33 0
00:36:59: TCP66: Telnet received DO ECHO (1)
00:36:59: TCP66: Telnet received WONT TTY-TYPE (24)
00:36:59: TCP66: Telnet sent DONT TTY-TYPE (24)
Supplemental Lab or Challenge Activity:
1. Try using telnet from a workstation into a router.
2. Use the debug telnet with a workstation accessing a router with telnet.
3. Try these commands again later when you have multiple routers set up in a
network.
4. Why would you not want to allow anyone to access your router with telnet? Why
would you?
5. Look at that telnet debug and figure out what is happening there.
6. Put a different password on each of the vty sessions. Leave one open. Then open
multiple sessions into that router. You can use the “terminal monitor” command
to see syslog messages as they are generated on that remote telnet session. Be
sure to try using show telnet, debug telnet, show users, show sessions, and show
debugging.
So What Have I Learned Here?
In Part 1 you learned how to use telnet to get to places on the web. Well…routers are on
the web too. So in this lab you learned about using telnet to your routers. In Part 3 you
will learn how to telnet into switches. You may use this someday to telnet into the
routers at work from your home…just think…no commute. Ahhh wouldn’t it be nice?
Guest Router Name Derivation
In 1982 William Gibson first coined the term “cyber-space” in his novel.
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