Static IP Address and DHCP Reservations

[David M]

When I first set up my NAS on my home network, one source suggested setting a static IP address. To make a long story short, the one that I chose did not agree with the one that the router provided. In the end, I set both a static IP address on the NAS and created a DHCP reservation on the router using the same address. Everything worked just fine after that.

But now, I'm beginning to think that this is redundant and that the best thing to do is to just have the DHCP reservation and set the NAS to get the IP address automatically. What is the best practices approach ?

 

[EAZ1964]

I do both as well. Just to prevent no IP or double IP in case one side fails.
A reservation in the router should be sufficient if you work bare minimum.

 

[jeyare]

best practice for the home LAN:
- define fixed range for the static IP addresses (all known devices in your LAN)
e.g. 192.168.1.2 - 192.168.1.60 ... up to your scenario. Strictly use this setup on both sides (router, device). You can get better manageable environment.

- define different fixed range for the dynamic IP addresses, mainly for an occasional devices which needs to be connected within your existing LAN (switch between wired and wireless operation for the same devices).
e.g. 192.168.1.150 - 192.168.1.220

- as you can see you can make a reserve for the ranges development (yeap, here is a point for precise subnet mask definition, but it’s over for newbies)

- in this both cases is better to use VLAN setup for each kind of devices pool what needs to be shielded or connection regulated within LAN. Specially for a Guest network - when the shield between your “trusted” network and the guest network must be defined.

 

[Robbie]

Another vote for doing both on a home / small office network.

All my known and 'trusted' regular clients and servers have a DHCP reservation set on the router (10.0.1.1 to 10.0.1.50 in my case) and 'trusted' pure DHCP clients have the address range above this (eg 10.0.1.51 and above). The more critical clients and servers in the 'trusted' reservation also have a fixed IP set on the device itself.

Untrusted but regular network clients (eg work laptops) get a DHCP reservation on the guest network/VLAN, with all untrusted visiting clients getting a pure DHCP from an address range above that segment.

This makes it easy to see what is going on via DHCP and make for easier firewall rules (eg to grant printer access from guest network etc). It also ensures that should DHCP fail (I use dnsmasq) all the critical stuff will continue as normal but enough regular clients will hiccup to let me know that dnsmasq / DHCP has had an oops.

As an aside I never understand why people use the 192.168.x.x private address range - too many numbers to type for my liking. 10.0.x.x is much easier on the fingers. I also like things to be very simple:

10.0.0.0 - LAN between router and modem
10.0.1.0 - LAN 1 main LAN
10.0.2.0 - LAN 2 etc...
10.0.3.0 - LAN 3

 

[fredbert]

As an aside I never understand why people use the 192.168.x.x private address range - too many numbers to type for my liking. 10.0.x.x is much easier on the fingers

Many businesses use 10.x.x.x so it's less likely to get overlap for home use with 192.168.x.x. If your business' VPN client permits local breakout then it could get confusing.

Back to LAN addressing and DHCP, my trusted LAN is /24 and:

• I allow x.x.x.2-99 for wired client reservations in DHCP
• x.x.x.102-199 for the same client's WiFi reservation in DHCP
• The actual dynamic pool of addresses for new trusted clients is x.x.x.240-254
• x.x.x.200-239 are spare at the moment until I need more IP in the pool or reserved.
• Some client's with DHCP reservations will use manual/static configuration (NAS's mostly).

This works with SRM DHCP service: I know that reservations can/should be in the pool but this split allows me to see what new devices I have.