in this forum I found that to log telnet access to routers (Successful/Unsuccessful - Authorized/Unauthorized) a possible configuration is:
access-list 10 permit 10.1.1.1
access-list 10 permit 10.51.21.34
access-list 10 permit 10.51.8.32
I find on cisco.com these syslog events related to telnet:
%TN-2-BADLOGIN : Bad login string pointer [hex]
%TN-3-BADSTATE : Illegal state [dec]
%TN-3-READLINE : Unknown return code [dec] from telnet_readline()
"%TN-2-BADLOGIN : Bad login string pointer [hex]" is related to unauthorized telnet access to the router?
Can you suggest me some syslog messages generated when someone tries to access a router?
Thanks a lot