Synology’s DHCP server
Frustrated by his router’s limitations, David Ludlow turned to his NAS to make his home network easier to use
When a device connects to your home network, it sends a request to your router asking for an IP address. Your router’s Dynamic Host Configuration Protocol (DHCP) server looks to see which addresses are in use, then it sends a spare one, so your device can connect to the internet.
DHCP works brilliantly, but the servers that are built into routers are typically quite limited and lack useful features. They can also be hard to use. More powerful is the DHCP server built into my Synology NAS drive, which shows me what’s connected to my network, lets me set the DNS servers I want, and quickly fixes IP addresses for important devices.
To switch to it, I first typed ipconfig into Command Prompt and noted down the Gateway address of my BT router (192.168.1.254). Next, I connected to my NAS drive’s web page (find.synology.com), then clicked Control Panel followed by DHCP Server. I then selected its network adapter (LAN 1) and clicked Edit.
To turn on the DHCP server, I clicked the ‘Enable DHCP server’ box ( in our screenshot above right), then needed to enter the Primary and Secondary DNS server addresses. The easiest option is to enter the IP address of your router, but you can change DNS servers (as I explained in Issue 629). I chose Google’s DNS servers here (8.8.8.8 and 8.8.4.4) 2 as they’re very reliable and fast.
Next, I added the ‘Subnet list’, which means the start and end addresses that the server will give out. This is where things get a little complicated. The start address needs to retain the first three numbers (each number being separated by a dot) of the Gateway’s address (192.168.1 for my router). But the fourth number depends on the fourth number of the Gateway address. If it starts with a 1, then the fourth number in the start address should be a 2 (192.168.1.2, for example). If the Gateway ends in 254 (as mine does), then the start address should end in 1 (192.168.1.1).
For the end address, again keep the first three numbers from the Gateway. You only need to change the fourth number if it’s 254 - mine is, so I changed it to 253 . I then entered the Netmask as 255.255.255.0 (that’s the same for all home networks) and the Gateway address I noted down earlier, and clicked Create.
You can’t have two DHCP servers running on the same network, so I disabled the one on my router. Settings differ from router to router, but for my BT router, I accessed its web management page, selected Advanced Settings, My Network, then changed the Enabled option under DHCP to Off,
Some devices benefit from having a fixed (or ‘static’) IP address, namely those that need to be frequently accessed by other systems or devices on the network, such as printers. The easiest way to create fixed addresses is to go back to the Synology DHCP server settings and click the DHCP Client tab. You’ll see a list of devices connected to the network. I find the device that I want and then click the padlock icon next to it: that makes the DHCP server always give the same IP address to that device.