Hi guys,
i do want to keep my local traffic local.
I do have a Synology NAS that I usually access from the WAN over his dyndns name. For that purpose I have set up all my mobile phones and the corresponding Synology apps to use this dns name. Once I am back at home, logged in to my local WIFI, I do not want the mobile phones to resolve the dns to a public IP and come in back from the WAN.
I tried to achieve this by using a static dns entry which points mynas.dyndns.org to its local IP, but this did not do the job…
Any simple solution to keep my local traffic local in the above described scenario?
Syno NAS
→ local ip 192.168.0.100
→ wan DNS Name mynas.org
Fritzbox
→ is used for WAN connections
→ uses port forwarding to the NAS (NAS is directly attached to a CRS125)
I figured it out myself and I would like to share my findings with you.
The very simple and straight forward solution with a static dns entry to the local NAS IP does actually work, BUT in my case only on my Windows Laptop.
Android devices still kept connecting from external. They somehow ignore the local static dns entry. I finally came to the conclusion that they must use a alternative DNS, which is most likely 8.8.8.8 Google and that keeps resolving my domainname to the public IP.
A working solution looks like the following #in the first step im am forcing a redirect to the local DNS (with the static entry)
/ip firewall nat
add action=dst-nat chain=dstnat comment=“Redirect Admin DNS” dst-port=53
protocol=tcp src-address=192.168.0.0/24 to-addresses=192.168.0.10
to-ports=53
add action=dst-nat chain=dstnat dst-port=53 protocol=udp src-address=
192.168.0.0/24 to-addresses=192.168.0.10 to-ports=53 #in the second step, which is specific to my network topology, I am adding exclusions for other Servers in my network that would be mistakenly redirected to the NAS ip
add action=dst-nat chain=dstnat comment=
“Redirect Admin XMPP clients to 192.168.0.115” dst-port=5222 protocol=tcp
src-address=192.168.0.0/24 to-addresses=192.168.0.115 to-ports=5222