3560G con0 loop.... please help!!

Unanswered Question
Apr 19th, 2009


I had a switch go down recently. In replacing said switch i dropped the config onto the replacement, copied running config to start and reloaded.

However, when it had booted back up, i was unable to connect back onto the switch via the console cable.

Its simply states that Con0 is now available, press return to get started. However when i hit return it flashes Authentication failed and then loops back to Con0 is now available, press return to get started.

Can anybody offer me advice on

a)what could be a possible cause of this and

b) how i could resolve the problem.

Thanks in advance


I have this problem too.
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jimmysands73_2 Sun, 04/19/2009 - 11:03

I am new to this, but I think the issue might be you might be attempting to have your sw attempt to reach a radius or tacacs for auth (bad for a local console port). You need to set it for local atuh (I believe its 'login local'). I could be totally wrong in my observation though.

To fix it boot your sw (if you have that luxury)...I followed this guide, http://www.petri.co.il/csc_how_to_recover_lost_password_on_cisco_switch.htm, but you can find something on ciscos site also, and change/observe your line con 0 config that way.



lee.foley Sun, 04/19/2009 - 11:39

Thanks Jimmy

I'll give that a try and feedback.

Thanks again


davy.timmermans Mon, 04/20/2009 - 06:30

If you are able to reboot the switch I would do the following:

reboot the switch

press on the mode button in order to come in rommon mode

switch: flash_init

switch: rename flash:config.text flash.config.text.temp


The switch will boot without any configuration because it can't find config.text.

Answer 'no' for initial configuration


switch#copy flash:config.text.temp run


and then you've to look what's configured

aaa new-model

aaa authentication login default local


line con 0

login local

if this is true> check if there is a

user xxx secret/password xxxx is configured

I suspect that no user x secret xxx is configured.

Else you can help by posting all related config


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