Static IP addressing

forkvoid

What's the difference between creating a reservation in DHCP versus picking an IP out of scope and setting it statically on the client? Just management? Which one is best-practice? I would assume the reservation, as that means less configuration on the client, and you can clearly see what is taking what IP in DHCP without consulting DNS. Is there a reason to use manually-entered static IPs on servers, or is a DHCP reservation acceptable?

Hyper-Me

For servers, because they are generally fewer in number and easier to access by administrators, I always manually assign static addresses.

You don't want to take the chance on the DHCP server going down and the server dropping its lease and the whole network suffering because of it.

Clients, on the other hand, if they require a static IP I just give them a reservation in the DHCP scope.

Also, as rare as it may be, I have seen Windows Server DHCP servers lease an address thats already in use on the network. Lots of other DHCP servers (SoHo routers ,etc) don't even have the capabiility to check if an address is in use before leasing one out.

Lunchbocks

I also set my servers as static. However, for clients who need the same address, I set them up as DHCP with a reservation on the server. That way any changes on the server such as a new DNS address are automatically pushed to the client.

earweed

I believe the static IP address is especially important in a large enterprise environment. As the above poster noted about if the DHCP server went down or even if the DHCP server went to change the address the server would be unavailable for a short time. You want your server available always, which is best done with a static address. You also, if possible, never want to have to change the addresses of the servers as the problem of availability may come up.

Ahriakin

Also be aware if any of your network services (usually security related) rely on any kind of interaction with DHCP for host identification (e.g. DHCP Snooping reliant services on Cisco boxes, NAC appliances that primarily work with/through DHCP etc.). Personally I prefer reservations for anything non-critical or remote, statics for critical and local infrastructure that is easier to get hands on with.