Prevent Ballot Box Stuffing uses sessions/ cookies to determine the duplicate respondent. So, if participant takes the surveys twice from different browser then he/ she is allowed to take.
In order to prevent this, if you have some unique identifier for each respondent, then you can create a update contact action task, once the survey is completed by the respondent, where you can set an embedded data 'isCompleted' to 1. Now, at the start of the survey, ask the participant their unique identifier and using authenticator, check if they are present in the contact list, if present, show them the message they are already completed the survey and terminate them else let them continue with the survey.

Does it possible with IP Adress, too?
It would be the easiest way to filter doubble IP Adress...

We working with 2 or multiple panel providers and sometimes we collect same ip adress.
We would like to prevent the double ip adress from different providers.

Regards
Markus

Any updates on this?

IP address validation can cause problems. I am on a campus and we recycle IP addresses. So different people may get the same IP at different times.

Qualtric's documentation actually has a pretty good write up on this, https://www.qualtrics.com/support/survey-platform/survey-module/survey-checker/fraud-detection/
While none of these are perfect for an Anonymous link survey a combination of the tools are what we use when we need to ensure we are getting "good data". When the tools flag something as suspicious we will do a human review of the data as well, depending on how "safe" we need to be we'll determine if we toss suspected frauds or let the borderline ones through.