DDNS Syncronization issues

Hello every one,

I have 1 Surf Soho under test environment in a remote location.

This unit is used to give me access to a remote server using 3G connection. For the remote access we use DDNS (using our Pro accont from DynDNS) and port forwarding.

This is a very usual application we have and up to the moment we have been using 3G/4G routers from Linksys and TP-link but we are not very happy with them, so, as we already had a peplink Balance 380 and a 210 in our office and we are very happy with it, we dicided to test Surf Soho of this application to.

The test I we implemented was designed the following way:

  • USB is the primary WAN. DDNS account is set with a specific domain.

  • WAN is set as secundary WAN. The same DDNS account is set with the same domain.

If the USB Internet connection is lost, this one is turns on, synchronize DDNS domain and we have remote access to the remote server

If USB Internet connection is back, it synchronize DDNS domain and turns off the WAN. Remote access to the server is back again.

In normal situations, this is working OK, however, sometimes, (and this is the situatioan at the moment) the DDNS synchronization doesn’t works and we lost remote access to the server (and even to the Surf Soho) until there is change in the internet access point (from WAN to USB, or from USB to WAN, as the DDNS synchronization is done again and this time it might work correctly).

If the DDNS synchronization fails on the WAN connection, there isn’t much problem, as normally this means that there was a problem in the USB internet connection, and when this is back, the WAn is turn off and the DDSN synchronization will be performed for the USB (primary access). But if the one that fails is the USB, we can lose access to the remote server for a longue time, until the USB Internet connection is lost for some reason and the all DDNS synchronization process is done again.

In my opinion, there should be feature that allow us Surf Soho (or any other Peplink/Pepwave balance router) to check from time to time (for me, ideally every hour, but I would be already happy if every 6 hours, and not that bad if every day) if the actual Internet IP address is correctly synchronized in the DDNS server (compare IP’s), and if not, synchronize it.

As I do have a DynDNS Pro account, I am allowed to “force” more IP’s synchronizations. Even if the IP remains the same, but I think it makes more sense to use a “smarter” approach and first check if the IP is already sync or not. If not possible, a feature that forces a sync every “x” time also fits my needs :-P.

For the moment the solution I will implement will be:

  • As I am using a 3G/4G TP-Link 3020 with another USB Internet modem from another providor connected to the Surf Soho WAN, and this already have DDNS (with a different domain) and Wifi on, my plan is to go there and change the configurations of the all system the following way:

  • WiFi WAN will be set as primary Internet Access. Will use TP-Link WiFi to get the Internet access.

  • WAN connected by cable to the TP-Link will be the secundary Internet access

  • USB Internet will be third Internet access.

In Surf Soho, all WAN’s (WiFi WAN, WAN and USB) will be configured with the same DDNS configurations, with the same domain name.

In TP-Link, will have a different DDNS seting with a different domain name.

This way, if for some reason the DDNS Sync doesn’t work the correct way in Surf Soho, I still have access to TP-Link (using the other Domain Name) and will be able to disconect WiFi. This will activate the WAN in Surf Soho to be the new Internet access and will “force” a new DDNS sync. Then I can Activate WiFi in TP-Link again, and the WiFi WAN will be back in Surf Soho, with a new DDNS sync.

The other way around, is to check in my DynDNS account what is the IP set in the other DDNS account (the one in TP-Link) and change it by hand.

But all this are workaround that will allow me to get access to my remote server without the need to drive 100km in both directions. The best solution is that I have Surf Soho cheching from time to time if the DDNS sync is OK or not.

We have at the moment more them 20 of this servers and the idea is to install a Surf Soho in every one of them and replace the TP-Link 3020 by a Pepwave Surf On-The-Go.


Nuno Olivença

Hi Nuno,

I really appreciate your taking the time to write up this detailed story. This all makes perfect sense.

We will review the DDNS mechanism and help you get around this issue elegantly. We will come back. Thanks.

Hi Keith,

Thank you very much for your fast reply on my post in the forum.

I also appreciated very much that you did considered that my comments makes a lot of sence and that you will review the DDNS mechanism to help me to get around with this issue elegantly.

As I told you, I am very happy with my Peplink/Pepwave devices. They perform very well, the interface is very intuitive and easy to use, the support page is very good with a great forum, and every time I had a problem (that up to the moment was simply a question of integration of new USB 3G modems in to the list of compatibility USB modems), the support was really fast to react and solve my problem.

I only have good things to say about Peplink/Pepwave, and it seams to me that I really have no reasons not to keep doing it.

Best Regards

Nuno Olivença

Hi Nuno,

Thank you for your compliments. We have a passionate team and we love what we do! Having happy customers like yourselves is the reward that keep driving us forward.


Hi Nuno,

I have a good news for you. This feature enhancement will be rolled into the 6.1.1 maintenance update which is scheduled in the next month or so! Cheers.

Thank you very much for this info Keith.

I really appreciated the effort from your side.

Best Regards