Connections a device is making on the internet (wifi extender)

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I bought a wifi extender which hasn't arrived in the mail yet. I'm starting to get nervous about bringing some random device into the home and was wondering if wireshark could help me monitor a device. Will this program report the activity of a device on a home network? Theoretically if I'm watching a movie for half an hour there should only be a few websites being contacted and the extender should match this.