Configuration for Synology (NAS)

Important

To use DynDNS a DNS API user MUST exist. To do that follow the guide Create User in Customer Portal!

For all domain customers we offer a DynDNS service which communicates with the Servercow nameservers via the Servercow DNS API.

In the following article you will learn how to connect your Synology NAS¹ to the DynDNS interface of Servercow in order to use the DynDNS service and get direct access to your NAS via FQDN².

Via External Access (UI) - IPv4 Only!

Danger

Although this option is the most convenient method for Synology NAS, it is only designed for IPv4. IPv6 is only possible in the manual variant via CLI! See also: Via Bash Script (CLI) - Dual Stack (IPv4 & IPv6) capable

1. Open your NAS in a Browser and login with a Admin User

   Notice

   If you do not know the IP of your NAS, it is best to use the Synology Assistant to find your NAS on your network.

2. Open the settings for external access on your NAS:

   Control Panel > Connectivity > External Access > DDNS
   

3. Click on Customise Provider there.

4. Enter the following information in the Service Provider & Query URL fields:

   • Service Provider: Servercow
   • Query URL:

     https://www.servercow.de/dnsupdate/update.php?username=__USERNAME__&pass=__PASSWORD__&hostname=__HOSTNAME__&ipaddr=__MYIP__
     

   

   Danger

   Please do not fill in the data between the underscores (__)! The NAS automatically recognises the placeholders and fills them in.

5. Add a new DynDNS login by clicking on DDNS > Add. Please enter the information there as follows:

   • Service Provider: Servercow
   • Hostname: Your subdomain/domain which should be updated via DynDNS (e.g. dyndns.yourdomain.com)
   • Username/Email: Your DNS API User
   • Password/Key: Your DNS API User Password
   • External Address (IPv4): The public IPv4 address of your connection. (Mostly automatically detected)

   

   Success

   If you have set everything correctly, the status at Test Connection should change to normal and light up green.

   

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Via Bash Skript (CLI) - Dual stack (IPv4 & IPv6) capable

Notice

These instruction assume that your NAS is accessible via SSH. If this is not the case, please activate SSH access to your NAS using these instructions!

1. Login to your NAS via SSH by using a Admin User.

   Notice

   If you do not know the IP of your NAS, it is best to use the Synology Assistant to find your NAS on your network.

2. Change to the root user by typing sudo -i and authenticate with the password of the current user.

3. Create a new bash script in one of your created volumes e.g. /volume1/data with the name ddns.sh and the content:

   Dual-Stack (IPv4 & IPv6)Nur IPv4Nur IPv6

   /volume1/data/ddns.sh

   #!/bin/bash
   if [ -f /tmp/old_ip4 ]; then
   IP4_OLD=$(</tmp/old_ip4)
   else
       IP4_OLD=none
   fi
   
   IP4_NEW=$(curl -s ip4.mailcow.email)
   if [[ "${IP4_NEW}" != "${IP4_OLD}" ]]; then
       curl -s -X POST 'https://api.servercow.de/dns/v1/domains/IHRE_DOMAIN.tld' \
       -H 'X-Auth-Username: IHR_API_BENUTZER' \
       -H 'X-Auth-Password: IHR API PASSWORD' \
       -H 'Content-Type: application/json' \
       --data "{\"type\":\"A\",\"name\":\"subdomain\",\"content\":\"${IP4_NEW}\",\"ttl\":60}" -o /dev/null
   fi
   echo ${IP4_NEW} > /tmp/old_ip4
   
   if [ -f /tmp/old_ip6 ]; then
   IP6_OLD=$(</tmp/old_ip6)
   else
       IP6_OLD=none
   fi
   
   IP6_NEW=$(curl -s ip6.mailcow.email)
   if [[ "${IP6_NEW}" != "${IP6_OLD}" ]]; then
       curl -s -X POST 'https://api.servercow.de/dns/v1/domains/IHRE_DOMAIN.tld' \
       -H 'X-Auth-Username: IHR_API_BENUTZER' \
       -H 'X-Auth-Password: IHR API PASSWORD' \
       -H 'Content-Type: application/json' \
       --data "{\"type\":\"AAAA\",\"name\":\"subdomain\",\"content\":\"${IP4_NEW}\",\"ttl\":60}" -o /dev/null
   fi
   echo ${IP6_NEW} > /tmp/old_ip6
   

   /volume1/data/ddns.sh

   #!/bin/bash
   if [ -f /tmp/old_ip ]; then
   IP_OLD=$(</tmp/old_ip)
   else
       IP_OLD=none
   fi
   
   IP_NEW=$(curl -s ip4.mailcow.email)
   if [[ "${IP_NEW}" != "${IP_OLD}" ]]; then
       curl -s -X POST 'https://api.servercow.de/dns/v1/domains/IHRE_DOMAIN.tld' \
       -H 'X-Auth-Username: IHR_API_BENUTZER' \
       -H 'X-Auth-Password: IHR API PASSWORD' \
       -H 'Content-Type: application/json' \
       --data "{\"type\":\"A\",\"name\":\"subdomain\",\"content\":\"${IP_NEW}\",\"ttl\":60}" -o /dev/null
   fi
   echo ${IP_NEW} > /tmp/old_ip
   

   /volume1/data/ddns.sh

   #!/bin/bash
   if [ -f /tmp/old_ip ]; then
   IP_OLD=$(</tmp/old_ip)
   else
       IP_OLD=none
   fi
   
   IP_NEW=$(curl -s ip6.mailcow.email)
   if [[ "${IP_NEW}" != "${IP_OLD}" ]]; then
       curl -s -X POST 'https://api.servercow.de/dns/v1/domains/IHRE_DOMAIN.tld' \
       -H 'X-Auth-Username: IHR_API_BENUTZER' \
       -H 'X-Auth-Password: IHR API PASSWORD' \
       -H 'Content-Type: application/json' \
       --data "{\"type\":\"AAAA\",\"name\":\"subdomain\",\"content\":\"${IP_NEW}\",\"ttl\":60}" -o /dev/null
   fi
   echo ${IP_NEW} > /tmp/old_ip
   

   Q: Why don't we just create the file in the /root directory or somewhere else?

   A: When updating the DSM³, it can happen that all files that are not explicitly located on a created storage pool are deleted. For example, after a major update.

4. Make the ddns.sh file executable:

   chmod +x /volume1/daten/ddns.sh
   

5. Open your NAS in Browser and Login as Admin user.

6. Navigate to the Task Scheduler in options:

   Control Panel > Task Scheduler
   

7. Create a Scheduled Task > User-defined script there:

Success

If everything has been set correctly, the DDNS update job runs every 10 minutes, every day. If necessary, the time until the next run can be decreased/increased at any time.

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1. Network Attached Storage ↩

2. Fully Qualified Domain Name ↩

3. Disk Station Manager ↩