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Synology External Access

Synology Aug 24, 2021
Access your Synology remotely from a DNS

In this guide, we will be setting up our Synology external access. This can either be with an official domain name or a free dynamic one. Free DNS is also referred to as DDNS services.

Static IP

To access your Synology NAS internally, you first need to set up a static IP. So, you can forward the external connection from the internet to your Synology. When we are talking about a static IP in this case, we do not refer to having an external static IP. Specifically, we want the Synology NAS in your network to have a static IP.

This only applies if your Synology does not have a static IP assigned yet

  1. Login into your DSM with an administrator account
  2. Open Control Panel
  3. Open Network
  4. Go to the tab Network Interface
  5. Select LAN 1
  6. Click Edit
  7. Set IPv4 to Use manual configuration

    Now you’ll need to enter the information from your home network. You have to set the IP address to an address that is not within the DHCP pool. Also, make sure you set the gateway and DNS server to your router’s IP address.
  8. Click OK
  9. Restart your Synology
  10. After restarting, your Synology should now be accessible in your home network from the assigned IP number.

Router Configuration

This part is actually out of the scope of this guide. Generally, what you need to do is to configure your router firewall and NAT port forwarding. Thus, allowing network traffic from the internet to your Synology NAS and forwarding this traffic from the internet to the static IP number of your Synology. This ensures your Synology can be accessed externally from the internet.

You have to forward the following traffic

NAT Port Forwarding table

Please note that UDP is not explicitly required

You might have to consult the documentation of your router.

This guide will be updated on achieving this with a Synology Router running SRM.

Dynamic DNS

Setting up your Synology with external access DNS or even DDNS is relatively easy with Synology DSM. When I reference DNS in this guide, it can be considered a synonym for a DDNS (Dynamic DNS).

Please note that if you’re Synology is unable to determine your external IP, you might have to visit to obtain your public IP address.

In order to configure a dynamic IP follow the following steps.

  1. Login into your DSM with an administrator account
  2. Open Control Panel
  3. Open External Access
  4. Goto the tab DDNS
  5. Choose Add
  6. Choose a Service Provider; if you’re unsure choose, Synology
  7. Now you can enter a Hostname and choose a suffix.
    Your DNS name will become your hostname.suffix, such as
    The domain name must be available. Also, you can check with Test Connection, but the wizard will check that for you.
  8. Set Heartbeat to Enable ; this will configure the Synology service provider to check if your NAS is online and available.
  9. In External address(IPv4), it should show your public IP; if there is not a public IP, you should go to to obtain your public IP and use Set External IP to configure it.
  10. Agree to the Terms of Service and click OK
  11. After a few seconds it should say in the column StatusNormal

Official Domain Name

Configuring your NAS to work with an official domain name can be a little more complicated because it requires configuration with an official provider. I will not be listing the actual configuration because this will be different for each hosting provider which provides a DNS redirect service.

In order to set it up you are required to obtain the following.

  1. Register for an official domain name like a
  2. Obtain a DNS Redirect service from a hosting provider.
  3. In your hosting provider’s DNS redirect dashboard, redirect your domain name to your public IP number, as shown by
  4. Wait until the hosting provider has updated their DNS services; with some providers, this can take up to several hours.

DNS Redirect Technical Details

In this example the public IP is: and the domain name is

MX@10 example.com1H
DNS redirect configuration

This DNS redirect configuration will configure the following

  • Redirect registered domain name to
  • Create an alias with will redirect all subdomain also to this IP *
  • Setup a www alias for your website
  • Create an email server alias
  • Create an email record (MX) which will allow you to run your own mail server


This guide aims to help you set up your Synology external access with either an official DNS or DDNS (Dynamic DNS). I migrated this guide from my earlier attempt to start a blog. Soon I will update this post and add some additional information that, as of now, needs to be highlighted. Mainly I will edit this post or create a new one to achieve this with a Synology Router running SRM. Please let me know what you think about this guide and how you want me to improve it. And, of course, feel free to email me with suggestions for topics.