Would it please be possible to add an option for the following:
after detecting an IP change, lookup my hostname first before updating with the dyn dns service
only update if the looked-up IP is still out-of-date
This prevents unnecessary updates when the cache file is missing (on first run) or is stale for some reason.
I have two clients updating the hostname: one on my desktop computer (ddclient) and one (or more) on mobile phone (running under Android OS). I use them both becase neither is very good when run alone for my setup.
I keep my desktop computer shut down for significat amounts of time, during which my IP can change in the router . My phone stays on much longer than my desktop computer, So by the time ddclient (running on my desktop) detects an IP change, the other client might have already updated the hostname ip with the dyn dns service.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
At first glance, I tend to agree. I would consider DNS lookups to be much less intrusive than update requests and would not want to risk being flagged as abusive and have my ddns host disabled.
However:
You only stand a chance of looking up the true status of the entry if you can reach the authoritative DNS server directly. If you can't, you'll probably be using cached data with a remaining TTL of 0-600 seconds, perhaps more. This means that at least in some cases, you'll update based on old data and some of these updates will again be unnecessary.
Also, how often does an IP address change and how many parallel ddns-clients are you running?
My IP normally changes once every 24 hrs I have my router update my ddns host upon receiving a new IP and since this does not work in 100% of the cases, I run DDC additionally. In this setup, usually DDC does one unnecessaray update every 24 hrs (necessary only if the router's update didn't go through). I don't think any provider will consinder one unnecessary update in 24 hrs abusive. Even one per hour should not get anyone rattled.
To sum it up, I would say there is not enough merit to justify the added complexity of the code or additional dependencies needed to add this functionality.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello,
Would it please be possible to add an option for the following:
after detecting an IP change, lookup my hostname first before updating with the dyn dns service
only update if the looked-up IP is still out-of-date
This prevents unnecessary updates when the cache file is missing (on first run) or is stale for some reason.
I have two clients updating the hostname: one on my desktop computer (ddclient) and one (or more) on mobile phone (running under Android OS). I use them both becase neither is very good when run alone for my setup.
I keep my desktop computer shut down for significat amounts of time, during which my IP can change in the router . My phone stays on much longer than my desktop computer, So by the time ddclient (running on my desktop) detects an IP change, the other client might have already updated the hostname ip with the dyn dns service.
At first glance, I tend to agree. I would consider DNS lookups to be much less intrusive than update requests and would not want to risk being flagged as abusive and have my ddns host disabled.
However:
You only stand a chance of looking up the true status of the entry if you can reach the authoritative DNS server directly. If you can't, you'll probably be using cached data with a remaining TTL of 0-600 seconds, perhaps more. This means that at least in some cases, you'll update based on old data and some of these updates will again be unnecessary.
Also, how often does an IP address change and how many parallel ddns-clients are you running?
My IP normally changes once every 24 hrs I have my router update my ddns host upon receiving a new IP and since this does not work in 100% of the cases, I run DDC additionally. In this setup, usually DDC does one unnecessaray update every 24 hrs (necessary only if the router's update didn't go through). I don't think any provider will consinder one unnecessary update in 24 hrs abusive. Even one per hour should not get anyone rattled.
To sum it up, I would say there is not enough merit to justify the added complexity of the code or additional dependencies needed to add this functionality.