Posted: Fri Sep 30, 2022 20:41 Post subject: Question about DDNS Force Update Interval
Hello,
I use the DDNS service of freedns.afraid.org, and it has worked well for me.
In June of this year, I replaced a Netgear R7000 with a R7800. In July, I left home for the rest of the summer and I took the R7000 with me to give to a relative. Without giving it much thought, I hooked up the R7000 at my relative's house before I had a chance to reset the configuration. The R7000 overwrote my DDNS record entry at freedns.afraid.org, and replaced my IP address with my relative's IP address. After that, I reset the configuration of the R7000.
I was gone for 2.5 months. The R7800 has the Force Update Interval set to the default value of 10 days, so I would have expected that my IP address would have been restored at freedns.afraid.org within 10 days, but it never was. I believe that the R7800 went no further than verifying that the actual IP address matched the cached IP address, and never updated the record at freedns.afraid.org. When I got back home a couple weeks ago, I went into the DDNS tab and looked at the settings, clicked Apply Settings, and the record was restored at freedns.afraid.org.
Is there a bug in the Force Update Interval function? It seems like Force Update Interval should attempt to update the DDNS record at the DDNS service every XX days (as specified in the Force Update Interval option) regardless of any cached values. Admittedly, this was a pretty unusual situation that is unlikely to repeat. I have certainly learned my lesson about resetting a router configuration before giving away a router.
I have "Use External IP Check" set to No. The gifted router was reset to defaults in July and no longer has my DDNS account credentials.
I figured there is a better way to test this to see if it is functioning as I would hope it would.
It's Sunday evening, and I just set "Force Update Interval" to 1 day and rebooted the R7800.
After rebooting, I logged into my account at https://freedns.afraid.org/dynamic and manually set the IP address to another address that is not my current WAN IPv4 address.
It has now been two days since I set Force Update Interval to 1 and manually changed the DDNS record at afraid.org, and the record has still not been restored to the proper WAN IPv4 address. To get DD-WRT for force an update, I tweaked the credentials, clicked Apply Settings, put the credentials back, and clicked Apply Settings again, and the proper WAN IPv4 address was restored at afraid.org.
The DDNS tab's help panel has two entries for Force Update Interval:
Quote:
Force Update Interval:
Type an integer number in the box to set the force update interval (in days). Updates should only be performed automatically when your IP address has changed. Be aware of your DNS provider's update abuse policy to avoid having your hostname or domain blocked.
And after clicking More this is displayed:
Quote:
Force Update Interval
Type an integer number in the box to set the force update interval (in days). Force update is an update which will be done although your IP address is still the same. Force update is required, especially for non donator of dyndns.org users, in order to avoid the host name of being deleted.
The second entry more clearly states how I think the function should work.
However, it seems like Force Update Interval is broken. If the DDNS record at the DDNS provider is somehow set to the wrong IP address value, I do not think you can depend on the Force Update Interval function to ever restore it back.
One missing piece of this puzzle is, we have no idea what build you're running, nor do we have a larger picture of your overall configuration that may affect this (i.e. WAN configuration). _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio
My ISP is Comcast and I have an ARRIS SURFboard S33 connected to the R7800.
The WAN Connection Type is "Automatic Configuration - DHCP."
I have had this configuration with DD-WRT and afraid.org for more than a decade after moving away from a fixed-IP DSL connection. It's always worked fine and DD-WRT has always done a great job of detecting a changed IP address and updating the record. This is the first time I have ever needed Force Update Interval to work, and frankly, I probably will not encounter this again. However, it would still be nice to see it fixed because it would make the DDNS function more robust.
By the way, there is an interesting backstory about how I discovered this, but it's not that relevant to finding a good recipe to make it easy to repeat the problem and fix it.
I had an old IP Power 9258S switch that I used to cycle power to my PCs while away from home, and accessing it remotely depends on the DDNS record at afraid.org, along with a static port forward in DD-WRT. It died just before leaving home for 2.5 months, and I replaced it with an MSNSwitch (https://www.amazon.com/gp/product/B081TKJJBS) that basically has the same functionality. A couple weeks after leaving home I was unable to access the MSNSwitch, but my other connected devices, such as a Ring doorbell, Ecobee thermostat, and garage door opener, were all available and working fine. Since the MSNSwitch was new, I figured that it suffered infant mortality.
When I get back, I found that the MSNSwitch worked fine on my local network. As I mentioned above, I gave the R7000 to a relative. However, what I did not mention is that I maintain the router for the relative too, and run DD-WRT on the relative's router and maintain another IP record for the relative's ISP. It was not until I was trying to debug the failed MSNSwitch that I logged into afraid.org, and that is when I noticed that the relative and I had the same IP address for our afraid.org DDNS records. Then I wondered why DD-WRT did not do a forced update to restore the record within 10 days? I was gone for 2.5 months. I also know that the power was out a few times, and the R7800 would have rebooted at least a few times.
Anyway, as I mentioned, this is not very relevant now because it's easy to simply alter the DDNS record and then confirm whether or not DD-WRT does a forced update. Even if the issue is never fixed, now that I am aware of the issue it will be easy enough to avoid.
I would test using the external IP check and not the internal IP check code (change "Use External IP Check" to "Yes") to verify that works without human intervention. _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio