You might want to check your router to see if you've assigned a static / reserved IP address for the machine in question too Col. If you're trying to get a fresh IP address you'll always get the same one if your mac address has a reserved IP address in the router and you're using DHCP. You'll also get the same IP address if your lease is still current for your current IP address, or you've hard coded your IP address at the Windows level.
A few things to consider anyway. What's the problem you're facing?
Besides some network gear just keeps stuff cached longer than it should not clearing up and renewing values so a clean occasionally can help before problems occur, that is switch off switched/routers for 30+sec then switch on again and they should repopulate values cleanly. I’m not a network guy just got oddball stuff i do when i get network problems and they seem to sort out for me.
