Network Engineering Stack Exchange is a question and answer site for network engineers. It only takes a minute to sign up.
Sign up to join this community
Pretty simple question.
What is the industry best practice? In a small business which has computers which require static IP addresses is it better to set static IP addresses for devices on the devices themselves, or in the router/managed switch? All non-static IP requiring devices can use DHCP.
Thanks.
This is what I think you're trying to ask: When I have a DHCP network but want a handful of hosts to have static IPs, is it best to reserve the IPs on my DHCP server or set static IPs on the hosts themselves? If that's your question, edit it and I'll take out this paragraph.
The only benefit I see of configuring static IPs on select hosts themselves is that the address is permanently set and not relying on the interface's MAC to reacquire the "reserved" IP. However, reserving the address already handed out by DHCP is quick and easy and doesn't require any access to the host. For instance, if I put a wireless print server on my WLAN and want it to maintain a specific address but don't care what, I can reserve the address it is assigned without ever touching the print server.
As an aside, you mention this is a small business. For an office of five or 10 people I would personally set static IPs as a best practice. No DHCP server needed, nothing ever changes, and perhaps it adds just a tiny extra bit of security in that one can't just plug a device into the network and have instant access.
Theres advantages to both approaches. It's down to you to decide which is more relavent on your network.
The advantage of setting on the device is that the devices can still talk to each other if the dhcp server goes down or if a rouge DHCP server shows up.
The advantage of setting on the DHCP server is that you don't have to go round to every machine individually if you ever need to do a mass renumbering.
If you are planning a long term network, I guess you should use static IP address on your workstations, so that you can apply security policies on a domain controller, or control Internet access by user profiles. DHCP is the perfect way when you don't need to apply special policies to specific users, all PCs shares a profile and do what it permitted.
Consider yet another scenario. Imagine you have an external WIFI dongle, it has its own MAC address. Now if it stopped working and you will have to replace it, or you decided to change connection type to cable, the MAC address will change, so the IP to MAC assignment will become out of date. If you want to have stable static IP not dependent on the MAC address of the device responsible for connection, then configure static IP on the computer connected to the router, ignoring DHCP. If you are ok with having IP-MAC dependency, then you can configure it on Router's DHCP.
Here's a huge disadvantage to setting a static IP on the host that ran into. I had set an NAS with a static IP of 192.168.1.195. Then I got a new router that insisted on working within the 192.168.68.xx range. I COULD NOT get access to the NAS, even resetting it didn't work. I eventually had to set the old router back up just to get access to the NAS to change it back to DHCP so that I could access it on the new router. If I didn't still have the old router, I'd have been hosed.
In a small business installation any disruption to the network will often require a professional to look at. For simplicity using DHCP with reservations is preferred.
Adding/removing device to the network will only require connecting them. When a laptop is moved to another network (home) they user won't be required to manually switch back to DHCP.
When reaching address exhaustion it will be clear what devices have reserved addresses (generally servers) making subnetting simpler.
It greatly reduces the chance that a novice have two devices with the same IP address.
