Pix 8.0(3) - Telnet not working

Unanswered Question
Apr 11th, 2008
User Badges:


I configured a Pix firewalll for telnet using the command "telnet ip netmask interface_name" but for some reason it does not wokr.

i checked the configuration on the firewall and the other device accessing the pix with telnet do not have additional configuration.

From wireshark capture I can see the pix replies my telnet atempts with a tcp rst packet.

Do you know what could be wrong in the configuration?


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Maxim Zimovets Fri, 04/11/2008 - 04:09
User Badges:


You did not specified the interface name.

AFAIK pix does not allow "clear" telnet on its outside interface. On inside this should work.

With best regards.

deephazz02 Fri, 04/11/2008 - 05:15
User Badges:


I configured telnet on the inside interface.

It is no possible to configure telnet without specifying an interface.


manjula.dealwis Fri, 04/11/2008 - 05:20
User Badges:

Are you telnetting from the outside? Then you need to give permissions in access-lists.

deephazz02 Fri, 04/11/2008 - 07:09
User Badges:


I telnet from the inside interface.

This is really strange, I thought a first that it would be a fw issue but since I get a tcp reset packet from the firewall, it's no an access list issue.

I'm a bit lost.


scdugan Sun, 04/13/2008 - 18:54
User Badges:

Instead of troubleshooting the telnet problem, configure SSH instead. You shouldn't be using telnet due to the security risks of device management over a cleartext protocol.

Command is:


I use putty for my ssh client, but there are plenty others out there.

manjula.dealwis Mon, 04/14/2008 - 04:45
User Badges:

Thats make things more easy. Because you can debug SSH connections. where as telnet doesnt have such an option.

But still we didnt resolve the telnet issue. If possible try to do the configuration from the scrach. The reason I suggest this is I had a connectivity issue with a PIX 515 and no matter what I did, no packets were going through the PIX to outside.This happen all of a sudden. So I did a fresh configuration and It worked (Though this is not a good solution ;-)

deephazz02 Mon, 04/14/2008 - 05:03
User Badges:


It works with SSH but does not with telnet.

Regardless of the security issue that comes with Telnet, it's still quite frustrating not to understand the reason why it does not work.

The configuration is the exact same conf as the one I use for another station, which works ok.

Although it didn't fix the issue, thank you all for your answers.


This Discussion