Foscam Synology DS218play User Manual page 33

If you don't know the DNS server, you can use the same settings as the Default Gateway.
4.3.2 DDNS
If you need Foscam DDNS, you can apply it on DDNS page.
First Enable DDNS, then select "myfoscam.org" from DDNS Server list, click "Get My DDNS Now".
Then login your Foscam Cloud account for myfoscam.org, and click "Get DDNS".
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