Setup dynamic update in my NAS. But it often ends up in failed state and leaves invalid settings in deSEC - because it wants to set TTL to 60. So it probably updates it every minute as well. What can be done about it?
For now going with CNAMES to synology DDNS, but this rules out setting main domain.
What update script are you using? And what failed and invalid settings is it doing? That an DynDNS would fail but issue an update command sounds extremly odd.
You make that setting in your update script? AFAIK deSEC does not allow for a manual config, besides the webGUI. If it is done via an update url, it is automatically set to 60. If you do it in the webGUI, you are forced to use something equal or bigger than 3600.
There’s very little control over how often Synology DDNS update runs beyond giving it the url. I guess it was doing it too often and was rate limited. What I considered wrong on the deSEC panel was that TTL 60 was shown in red as if invalid. Maybe that’s how gui shows there’s a blockade?
Anyway I’ve moved to a bash script running via timer on a Linux VM on the NAS. Since it observes necessary delays all is fine now.
Ahh yeah, that is just because a manual webGUI value below 3600 is not allowed. You can ignore that.
If you are looking for a Linux shell script: shamless plug
Happy to hear feedback.
Looks interesting. Could it be altered to allow multiple domains be updated? My current script does that, from a list of “domainA,subdomain.domainA domainB,subdomain.domainB” will do two requests to deSEC (I think different domains can’t be updated in one call).
edit: space separates domain sets, comma separates subdomains for one call.
You could just have multiple scripts and cronjobs.
I don’t really need it, since it work mostly with CNAMES.
This is only partially true, depending on your definition of “domain”.
Some recent changes in the IP Update API now make it possible to update multiple hostnames in the same domain (zone), even with differing IPs (or prefixes). See: Per-hostname IP Address Specification.
However when dealing with different domains (zones), separate updates must be made for each. The CNAME solution might be easier to manage and avoids running into Rate Limits.
HTH
fiwswe
PS. I think this was already answered, but just to be clear: The IP Update API automatically sets the TTL of changed RRsets to 60. Any other method of modification has a lower limit of 3600.
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