[Solved] How to use DDNS to connect Synology Active Backup for Business (ABB) on client

Basiclly, if your NAS had register DDNS, you just only need to make sure the port forwarding has been enabled for port 5510.(This is for ABB Windows platform.)

To check Synology service port list -->
https://kb.synology.com/zh-tw/DSM/tutorial/What_network_ports_are_used_by_Synology_services

Go here to check NAS port status -->
https://www.yougetsignal.com/tools/open-ports/

BUT, if the your DDNS is managed by Cloudeflare, then this way is a littlte different becasue Cloudflare only support as below -->https://developers.cloudflare.com/fundamentals/get-started/reference/network-ports/

HTTP ports supported by Cloudflare

80

8080

8880

2052

2082

2086

2095

HTTPS ports supported by Cloudflare

443

2053

2083

2087

2096

8443

There are 2 way to approch the demands.

1). A free way of Cloudflare - To create a CNAME record and disable proxied (IP is not masked that has risk be attacked, unsafe)

2). Subscribe ' Spectrum application' and with proxy in Cloudflare (hide NAS IP is more safe)

Here discuss the free way 1). only.

If the root NAS domain name as below manged by Cloudflare.

=> CNAME - yournas.abc.com - Dynamic IP - Proxied(Orange)

then need to add a CNAME record and disable proxy for a new sundomain name to ABB to by pass port limitation by Cloudflare.

=> CNAME - abbyournas.abc.com - yournas.abc.com - Non Proxied(Gray)

Then try again to check port status, it should be solved.

Finally, we can connect to ABB by NAS DDNS now.