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New Member

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


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



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

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,, but you can find something on ciscos site also, and change/observe your line con 0 config that way.



New Member

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

Thanks Jimmy

I'll give that a try and feedback.

Thanks again


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

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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