Securing Telnet

[sunjoseph]

How do I disable telnet sessions from the wan adapter but allowing telnet access from the lan network.

[jpoplawski · Accepted solution]

Two ways.

1) Add an ACL to your WAN interface

ip access-list ext InboundACL

deny tcp any any eq telnet

permit ip any any

int s 1/0

access-g InboundACL in

2) Create an ACL and apply it to the Line VTY.

access-list 10 permit 10.1.1.0 0.0.0.255

line vty 0 4

access-class 10 in

That should do it for a rough sketch, although you'll need to modify for your environment. I would recommend disabling telnet altogether and going with SSH, too.

Hope this helps, rate if it does,

JB

[sunjoseph]

I think i'm wrong on this issue but isn't the VTY the serial inerface? I wanted access from my internal network without plugging a cables into a special port.

[scottmac · Accepted solution]

VTY is short for "Virtual Terminal" (old system name for terminals is TTY).

VTY handles Telnet and SSH (for IOS that supports SSH)

Line Console is the serial port on the front.

Good Luck

Scott