By default, when someone responded to your survey, their IP address is recorded as metadata with your survey results.

You can edit your collector settings to control IP tracking in Anonymous Responses option.
Choose whether to:

• Block or allow survey access based on IP address
• Make survey responses anonymous

It is possible to track IP addresses to a single device, proxy server, or group of devices on the same network, but not possible to track per person. For example, the respondents who share a computer also share an IP address.

If you notice your survey was taken multiple times from the same IP address, it means either:

• An individual is responding to your survey multiple times
• Multiple people are taking your survey but they share the same IP address 

Note: There are more ways to track respondents, it depends on what collector type you use for sending your email.