Under your "line vty" enter "rotary x" where x can be 1-99. Then you can telnet your router at port 3000+x.
line vty 0 3
line vty 4
lets you telnet to TCP port 3004 to access VTY lines 0 through 3 using password "cisco", and TCP port 3005 to access VTY line 4 using password "backdoor". Note that this does not change the Telnet port number for the router: you can still get to it on TCP port 23. (If you need to block Telnet to the router on port 23, use access lists to deny access to that port from anywhere.)
Here's a link to the current documentation on "rotary":
Also, search the forums here for "line vty rotary" or "change telnet port 23" to see how other people are using it.
If you are looking to change the Telnet port number for security reasons, some people use NAT to translate port addresses. (Search forums here for "NAT telnet".) Others disable Telnet altogether and use Secure Shell (ssh). I usually just use ACLs to specify the IP addresses that Telnet sessions are permitted from.
We are pleased to announce availability of Beta software for 16.6.3.
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looking for early feedback from customers befor...
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