How To Set Up DHCP Reservations So You Never Have To Check An IP Address Again

Checking your computer's IP address every time you need it can get tedious. Here's how to set up DHCP reservations on your router so that each computer in your house has the same IP address all the time.

Whether you're using BitTorrent's web UI, forwarding ports for gaming, or streaming media to your phone, you sometimes need to know the IP addresses of your computers. The problem is, if you use DHCP (as most people do), those computers get re-assigned IP addresses every time you reboot them - which means you have to check what it is every time. You can avoid this hassle, however, with something called DHCP Reservations, which let you reserve specific IPs for each computer on your network. That way, they'll always have the same IP address and you never need to worry about checking it again.

Note: If you've heard of static IP addresses before, this is very similar. Since you manage it all from the router, though, it's a bit easier to set up. If, for some reason, you can't use DHCP reservations, you can set up a static IP on each of your computers instead, but this is our preferred method.

Many routers support DHCP reservations out of the box, but if they don't, you can always install the DD-WRT firmware, which adds the support to many more routers. Every router is a bit different, but in general, here's how to set it up:

  1. Head to your router's configuration tool by typing in your router's IP address in your browser's navigation bar. Usually this is something like 192.168.0.1. You can check it by running ipconfig in a Command Prompt, or heading to System Preferences > Network on a Mac.
  2. Find the DHCP reservation setting. This could also be called "DHCP Static Lease" or something similar. On my router, it was under the "Gateway" category.
  3. Head to the computer for which you want to reserve an IP address and find its MAC address. Once again, you can find this by typing ipconfig into a Windows Command Prompt, or by going to System Preferences > Network on a Mac, clicking on your Wi-Fi card or Ethernet port, hitting Advanced, and going to the Ethernet tab. Your MAC address will be in the form 00:00:00:00:00:00. Note that a Wi-Fi card and Ethernet port will have two different MAC addresses, and you can't assign them both to the same IP, so pick the one you use primarily.
  4. Type that computer's MAC address into the first entry in the DHCP Reservation setting. Then, type in the IP address that you want to reserve for that machine. Hit Apply, or whatever button is available to you.
  5. Repeat with any other computers that you want to reserve

You should now have a good list of computers with reserved IP addresses, like mine shown to the left. Note that you might have to renew your DHCP licenses on your computers for them to actually start using those IP addresses. You can do this by running ipconfig /renew and then ipconfig /release in a Windows Command Prompt, or by going to System Preferences > Network on a Mac, turning your Ethernet or Wi-Fi card off, and then back on again. If you then check your IP address (either with ipconfig on Windows or by checking the Network Preference Pane on your Mac), you should see that they have their new reserved IPs, which they'll use every time you turn them on.


Comments

    On a small home network it can be even better to statically assign your necessary addresses on the local device rather than a static assignment from your router. Quite often, you have to get the MAC address from the device, right it down them enter it on your router.
    Although it's marginal, you'll get a quicker boot time and there is no dependency on the router.
    I also use 10.1.1.1 for my router because it's quicker and easier to type.
    And other devices (e.g. NAS, WMC, Amp/receiver, PS3, etc) have easy to remember IPs, like:
    10.1.1.10
    10.1.1.100
    10.10.10.10
    10.1.1.3

      setting the ip on the device is no good for portable devices that use other networks because you will need to reconfigure for the new network and then manually configure everything back for yours when you get home. not worth the hassle at all

      i wish i knew that i could reserve addresses like this for the portable devices in my network...

      another great reason to do dchp reservations instead of dhcp assigning first available address is that if you use devices that sleep/suspend and you log on with another device while the first one is asleep, you can have them wake up to find the address taken and while its not the end of the world, its unnecessary and wastes your time.

      great tip here imo

        You can reserve addresses for mobile devices - it might be a bit harder to find the MAC address (iOS: Settings > General > About > Wifi Address), but once you've got it set up it's just a matter of disconnecting & reconnecting to get the new IP (alternatively, go into the Wifi Network settings and click "renew lease").

    Basic rule is if it's portable, assign a static IP, if it's portable (or you move it a lot, ie to LAN's), assign a reserved IP at the router.

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