Disabling telnet on port 6000-6032 to router w/ NM-32a

[aemr]

Hi,

I discovered it is possible to telnet to port 6000-6032 and 4000-4032 to start a console session to devices attached to the NM32A card.

This bypasses my security of allowing only ssh to vty 0 4 and then reverse telnet to the attached consoles.

How do I disable this and why is this disabled in the first place? I looked at some online docs which didn't help me understand.

Thanks in advance.

Art

[jsivulka]

I have no idea why you are seeing this behaviour. However, you can force the application to port mappings using a feature called PAM. This feature is a Cisco IOS Firewall feature and will protect your network by permetting the application to use only the port you specify. For more information, please see http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_configuration_guide_chapter09186a00800d981c.html