Auxiliary Port on a Router

Answered Question
Aug 21st, 2008
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I know this is probably going to be a stupid question but how do I disable a router's auxilary port. I know that to set it up you start with "line aux 0" in the configuration but I don't see where you can shut it down.

Correct Answer by Giuseppe Larosa about 8 years 10 months ago

Hello Doug,

try

line aux 0

transport protocol input none

transport protocol output none


So it shouldn't be used


Hope to help

Giuseppe

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Correct Answer
Giuseppe Larosa Thu, 08/21/2008 - 11:03
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Hello Doug,

try

line aux 0

transport protocol input none

transport protocol output none


So it shouldn't be used


Hope to help

Giuseppe

Syed Iftekhar Ahmed Thu, 08/21/2008 - 11:06
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There is not a command

for any router that will disable the aux port. However, you can probably use "autocommand exit" under "line aux 0" config, if you want

to prevent someone just to hook up a pc to the aux port and gain access to the box.



Richard Burts Thu, 08/21/2008 - 12:30
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Giuseppe


transport input none seems to be the default on the line aux since it does not show up in the running config after being configured:

R2(config)#line aux 0

R2(config-line)#transport input none

R2(config-line)#do sho run | begin line aux

line aux 0

transport output none

line vty 0 4


And while transport input none and transport output none are effective on the vty they are not effective on the aux. Here is what happens when I connect on the aux which has been configured with transport input none:


R2 tty1 is now available


Press RETURN to get started.


R2>who

Line User Host(s) Idle Location

0 con 0 idle 00:00:22

* 1 aux 0 idle 00:00:00


Interface User Mode Idle Peer Address


R2>


notice that the active session is on the aux.




Syed


autocommand exit is a very creative solution and I believe would be pretty effective. But there is a more simple solution which is highly effective. Under line aux 0 configure "no exec". Then if anyone should connect to the aux port there is no reaction and effectively the port is dead.


HTH


Rick

Giuseppe Larosa Fri, 08/22/2008 - 04:17
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Hello Rick,

thanks for your attention.

I had recently used an aux on a C2620 to connect to a the console of a C7206VXR.

And I had added transport input all or transport output all under the aux to fix it.

I remenbered about the no exec later.


Best Regards

Giuseppe

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