What scheme (if any) do you use to allocate internal IPs?

I've just finished implementing a new scheme on my router for handing out IPs for devices on my home network and it got me wondering what other people do.

I know the vast majority will just let their router hand them out via DHCP, but i've assigned each device a static IP ever since i bought a router capable of it more than a decade ago. With the ever increasing number of devices joining my network i was just assigning them IPs willy-nilly and my OCD started to twinge, so i spent some time devising a new scheme yesterday.

My router is a TP-Link WDR4900 running OpenWRT. The wired and wireless LANs are routed and not bridged, with both the 2.4GHz and 5GHz radios bridged together into one WLAN. The wired LAN has the 172.30.0.x/24 range of IPs and the WLAN has 172.30.1.x/24. The router also runs Avahi in reflector mode so that WLAN mDNS announcements can be seen from the LAN and vice versa.

Anyway, onto the IP scheme.

I decided that i wanted to keep everything consistent, so if device has both wired and wireless interfaces it gets the same IP in both ranges (e.g. a PS3 might have 172.30.0.53 for its wired interface and 172.30.1.53 for the wireless). If it only has one interface then the same IP in the other range is not reused by anything else.

172.30.x.2 - 172.30.x.10 are reserved for networking infrastructure (managed switches, AP, etc)
172.30.x.11 - 172.30.x.20 are reserved for physical servers
172.30.x.21 - 172.30.x.50 are reserved for virtual servers

I then give everyone in the house a block of 25 IPs and also reserve a block of 25 for generic house-hold devices.

The 172.30.x.201 - 172.30.x.250 block are left for DHCP to dish out to any guest machines brought onto the network.

Interested to read how other people handle things.

Strictly speaking that is a DHCP Reservation, a static IP is something that would be set manually on the device in question.

Moving on from technicalities ... Mine is very boring I'm afraid, everything is on a 192.168.1.10-192.168.1.249 scope - but I do give everything a reservation.

My systems - 192.168.1.10 ->
Other stuff - 192.168.1.50 ->
Media players/SmartTV etc - 192.168.1.200 ->

DHCP (and DNS) provided by 2 x Windows Server 2012 R2 servers on 192.168.1.5 and 192.168.1.6
Managed gigabit ethernet switch on 192.168.1.2
Router on 192.168.1.1 of course!

Very simply - everything is in the same subnet, wired and wireless.

Devices that are 'known' have static reservations.

As everything is in the same network there's no value to allocating different ranges to things, it'd be an unnecessary complication.

Zero point in providing everyone a 25 IP block of their own as, again, everything is in the same subnet. If I wanted to do that I'd segment the network into /27s and VLANs for each /27.

I may at some point place a second access point online for guests and place it in its own VLAN but right now there's no real value to doing that as I don't have many people packing laptops or tablets coming by and am not especially bothered by phones so just provide the wireless password.

That's it really. Nothing exciting. If at some point I need to start segmenting networks I will do so via VLANs and smaller subnets but right now things just work and no point in complicating them.

Why make it complicated!?

As I used to have a Speedtouch which used 192.168.1.254 so 192.168.1.0/24 network I have stuck with this. I changed my new Sky router to match.

DHCP range is from 101 to 200 and anything on a static is manually set out of this range but in the same subnet.

.5 has always been my network drive. Don't know why, just is.
.253 is my second router (used as a wireless access point for 5GHz WiFi)

My new network printer is just on DHCP as it doesn't seem to matter if the IP changes.

I like to know what devices are connected so I allocate an IP address on the network to each bit of kit, but have no system at all. I just pluck a number from the ether and slap it on the end of 192.168.0.
The modem/router allows me to define the MAC addresses to an IP address, blocking out any intruders. Too much hassle having a system...

In reply to a post by TMCR:

The modem/router allows me to define the MAC addresses to an IP address, blocking out any intruders. Too much hassle having a system...

That would not block an intruder capable of setting a static IP address.. but it would probably deter the average idiot.

IP address allocation is on the router, defined by the device MAC address, so someone being able to pick an IP address, idiot or otherwise, shouldn't get past that as they have to match the MAC address of a device I've entered into the router.

I wouldn't be so sure about that, if you are talking about a standard "Bind IP to MAC" feature on your router's DHCP server then if the client set a static IP then the router and manually enters the default gateway IP the router is not going to be smart enough to figure out that this guy has set a static IP and to disallow traffic. Moreso, the switch inside the router will be dumb and will stlll allow traffic to pass. You would need something like DHCP snooping or similiar to protect from people assigning static IP addresses.

My router has the ability to disallow traffic from any device not listed, so the MAC address is the key. If it was as easy as setting an IP address to gain access then this feature seems meaningless and I can't see why it would even be there. Yes, the IP address is allocated via DHCP and a table I've populated

In addition, there is a Wireless Filter List. MAC addresses are used to allow or disallow access. If the MAC isn't in the list then there's no access to WiFi, and that applies to smartphone, Kindles and so on, as we've discovered. I didn't mention this before as the topic was about assigning IP addresses, not security

It's very easy to assign a different MAC address to device.