login to your router:
'en'
'password'
'conf t'
'line vty <#1> <#2>' where #1 is the 1st line #, #2 last line #
'password 0 <password>'
'ctrl+c'
'copy run start'
rtr-gancr-1-gcore(config)#line vty ?
<0-1869> First Line number
rtr-gancr-1-gcore(config)#line vty 1 ?
<2-1869> Last Line number
<cr>
line vty 0 4
session-timeout 30
access-class 1 in
password 7 asdfasdfasdf
login
transport preferred none
transport input telnet
line vty 5 15
session-timeout 30
access-class 1 in
password 7 ertertertert
login
transport preferred none
transport input telnet
!