Over Christmas, my awesome wife bought me a Synology DS214 for my expanded home lab. One of the many reasons Synology was selected is because the DSM operating system supports multiple VLANs. However, the web interface only lets you set one interface. I found a number of conflicted articles describing how to configure the other VLANs. I upgraded my Synology to DSM v4.3 and then followed the process below to add the VLAN setup.

Depending on your switch setup, you may need to remove all VLAN configuration from the Synology’s port until the VLAN is created, or you can tag a single VLAN, or you can tag multiple VLANs and set a native VLAN. In a worst case scenario, you can connect the Synology to a port with no VLANs, configure the first VLAN, then move it to a properly configured tag. I trust the reader to understand and troubleshoot their local network configuration. If you do lose all connection to your Synology, you can always reset it to defaults and try again.

UPDATE: This process is confirmed to work with both DSM v4 and DSM v5!

UPDATE TWO: This will not work with DSM v6! See the comments for details.

Configure the networking for your primary VLAN. This can be done under Control Panel -> Network. Under the Gateway tab, add the default gateway and configure the hostname. Configure a DNS server (I would suggest waiting on Active Directory configuration, which will gray out this option, until after completing all networking). Switch the Network Interface tab and select the LAN interface. Specify the IP address and netmask as you would normally. Check the box to enable your VLAN, in my case VLAN 2. Apply the configuration. At this point, you may lose connectivity; check your VLAN config and re-establish connectivity before continuing.

You’ll notice there’s nothing in the Network control panel to configure a second VLAN. For our next step, we move to the command line. If you haven’t done so yet, enable the command line interface – using SSH, not telnet, of course. SSH to the synology and log in as root, with the admin web user’s password (Note to all vendors: Please stop doing this. Either allow admin to sudo or rip it out and just use root). You’ll be in the BusyBox shell, which should be familiar to linux users. We’re going to use a little script to add VLANs. You can copy this into your SSH client, or store it in a file and execute it manually, whichever is easier. If you only need to add one VLAN, I suggest the former; the more you need, the more appealing the latter option is.

Here are the parameters for my additional VLAN:

• Interface: eth0 [A DS214 only has one interface, larger units may use the bond0 interface or individual eth interfaces depending on configuration]
• VLAN ID: 5
• Address: 172.16.5.1
• Netmask: 255.255.255.240
• Broadcast 172.16.5.15

The script below sets variables containing these 5 values, calls vconfig to add a subinterface, brings up the interface, and creates an ifcfg script so it persists across reboots:

interface=eth0
vlan=5
ipaddr=172.16.5.1
broadcast=172.16.5.15
netmask=255.255.255.240

vconfig add $interface $vlan
ifconfig $interface.$vlan $ipaddr broadcast $broadcast netmask $netmask
cat > /etc/sysconfig/network-scripts/ifcfg-$interface.$vlan << END
DEVICE=$interface.$vlan
VLAN_ROW_DEVICE=$interface
VLAN_ID=$vlan
ONBOOT=yes
BOOTPROTO=static
IPADDR=$ipaddr
NETMASK=$netmask
END

After running this script, the VLAN configuration is live. If you go back to the Network control panel in the DSM interface, you should see an additional LAN interface. Repeat the script as many times as you need with additional VLAN configurations and ensure each shows up properly.

Though there is no absolute need, I would suggest rebooting the Synology at this point to ensure persistence across reboots, then proceed with configuring your other devices to make use of the new interfaces. It’s better to find out if there are issues now than when you have a power failure months down the road and lose access to some data because the interfaces went away.

Once you are sure your networking configuration is final, go ahead and finish your DSM configuration and start using it. Enjoy!