long delay for authentication failure

[xianglingzj]

Any guru here can help me on explaining a question about general authentication:

Normally when the authentication passes, it takes little time to see the result but when it fails, it takes much longer time to get a fail message. Why is that so?

[Jon Marshall]

It really depends on why it is failing. If it is failing because it does not get a response from the authentication server then it will try any other authentication servers in your list. This could take some time.

If the authentication server responds with either a success or failure there should be no real difference in the time taken.

Jon

[xianglingzj]

I think a lot of us have ever experienced this: When login to a TACACS+ enabled router, if you key in the correct pwd, it will grant you access almost in no time; whereas if you have any typo... hoho, better to get a cup of coffee from vending machine.

I would like to know what is happening within the long delay.