Does anyone know what is the default port open on Cisco 2600 router ?
I am going to block udp 137, udp 138 and tcp 139 from router, detail as below:
access-list 110 deny tcp any any eq 139
access-list 110 deny udp any any eq 138
access-list 110 deny udp anu any eq 137
access-list 110 permit ip any any
ip access-group 110 in
I found out the telnet port is open after I entered access list as above, therefore I am wodering how many ports have been open ?