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Not 100% sure, but I thought the command was <b>transport input none</b>.<br />

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As previously stated, transport input none will disable telnet. <br />
<br />
But why do you want to disable it?<br />

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for PCI requirments they need to disable telnet<br />
<br />
from transport input none<br />
<br />
but i can still telnet, and it says password not set<br />
that means port 21 is still open, and password is not set
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This will not allow any telnet access to the device (will &quot;stealth&quot; the port).<br />
<br />
access-list 23 deny any<br />
<br />
line vty 0 15<br />
access-class 23 in
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<div class="content wysiwyg-content">
how can i disable telnet service in cisco catalyst 3750<br />
i have done<br />
line vty 0 5<br />
transport none<br />
<br />
but when i do a scan, it shows port 23 is open
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how can i disable telnet service in cisco catalyst 3750
i have done
line vty 0 5
transport none

but when i do a scan, it shows port 23 is open

Not 100% sure, but I thought the command was transport input none.


As previously stated, transport input none will disable telnet. 

But why do you want to disable it?


for PCI requirments they need to disable telnet

from transport input none

but i can still telnet, and it says password not set
that means port 21 is still open, and password is not set

This will not allow any telnet access to the device (will &quot;stealth&quot; the port).

access-list 23 deny any

line vty 0 15
access-class 23 in

telnet service in cisco

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.

Routers

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.