If you’re using the Synology DNS server for your local clients or services on the Synology NAS, then you might need to clear it’s cache.
It’s really simple, and after googling I couldn’t find a straight answer. So I did some digging and found this was the appropriate way to clear the DNS Service Cache on a DSM6.x
- Login via SSH as root
- Run “/var/packages/DNSServer/target/script/flushcache.sh”