Generally speaking, residential modems use DHCP protocols for assigning IPs. Static IPs are available in some areas for a much higher fee than you'd otherwise pay for the regular stuff.
When it comes to your IP, the one that servers track is the one that's typically assigned to your modem, so any /release /renew commands would need to be issued on the modem itself, not on your computer, as all this would do is maybe give your computer a new IP address.
In short, no, you'll probably have to contact your ISP.
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