About technologies for your digital home

For beginners and tinkerers

Set-up DynDNS (DDNS)

March 18th, 2014

Set-up DynDNS

It is a good idea to implement a dynamic DNS (DynDNS, DDNS), in order to enable external access to your home server or NAS after installing them. I have used this feature already for few years. It is quite handy for example, when you are abroad or just travelling and you suddenly want to get some of your files from home, you just use an available Internet connection & grab your files. That’s it! You could call it a personal cloud 😉

Limitations

One of the limitations is an asymmetric internet speed.

That means that your download and upload speeds usually are different. In some cases, the ratio 1:10 is used. In my case, I have 30Mbps download speed, however my upload speed reaches only 3Mbps. So, if you connect from Internet to your home, you may expect 10x slower speed as you normally get at home. The majority of the users only realise this when they start to use access their home resources from the Internet.

In some situations, you may find out that the Internet access is limited.

For example from the university campus (WiFi, wired). The access can be limited only to certain protocols like http for WEB browsing and POP3 for e-mail checking.

Another limiting factor can be a non-standard SFTP port which was chosen by you. If you try to access your home network using such non-standard port, your network may be not reachable.

Different DynDNS clients

There are few ways of implementing dynamic DNS (DynDNS, DDNS), in order to reach your home. You may choose what suits you the best. The main point is that, the DynDNS client is needed to update the DNS record to your current IP address.

1st method using the router

It is the most universal method, because your router is on 24/7. So, it would just supplement your current router functions by performing additional task. The external access to your services (forwarded open ports) and DynDNS would be controlled centrally on your router.

You should read your router’s manual to clarify few aspects:

  • Can your router support that?
  • What DynDNS service providers are supported?
    (E.g. you can see the DynDNS providers list by DD-WRT below.)

In my case, I chose a router (access point), which supports DD-WRT firmware with the DynDNS support:

DynDNS-router

Here are some useful links for different vendors of wireless routers:

Belkin has its own instructions on how to setup DynDNS.

D-Link even has a  free dynamic DNS website dedicated for D-Link customers.

TP-Link provided the instructions how to configure DynDNS on their wireless. routers.

2nd method using the NAS

Some of the NAS vendors like Synology implemented the DynDNS client in their NASes. In this case, you could setup your NAS to perform as a DynDNS client.

Here are the Synology instructions on how to configure DynDNS.

If you own a D-Link NAS, this link could be used for that.

After you setup DynDNS

You should setup the port forwarding your router. Otherwise, no services will be accessible outside.

On DD-WRT enabled router, this can be done through NAT/QoS tab:

DD-WRT port forwarding

As you could see from the above screenshot, the default  SSH (SFTP) port was forwarded on DD-WRT to 8222.

Whatever method you choose, you will have subscribe to a DynDNS service provider. In some cases, your hardware vendor provides free access to such services (like D-Link).

Here’s a list of free DynDNS service providers:

Security

You should always remember that enabling external access is related not only with benefits, however with some residuals risks that someone could hack your home network.

Just follow some rules:

  • Keep your network all the time as simple (but not too simple) as possible. That will make easier to manage it .
  • Change all default passwords on your network gear and the machines.
  • Use at least eight symbols passwords.
  • For remote access to your machine use SFTP.

Enjoy your access to all your of digital library, anywhere! 😉