Had anyone figured out the behaviour of the DynDNS application in the 2820 dual WAN router with firmware 3.3.3?

There is the ability to set different host names for the two WANs and it has a setting for "Auto-Update interval" which defaults to 24 hours and can be set from 1 second to 10 days, but there is no explanation of what this does. The "documentation" <spit> - there as everywhere - is no more than a verbose recital of the screens and with no added information, examples or advice.

A well behaved DynDNS client will periodically (say every 5 minutes) check the WAN IP address and then compare it with either the last value sent in a forced update or else with the current value being returned from the DynDNS server and make a decision on whether a forced update is required. It will also force an update no less frequently than every 30 days to prevent DynDNS from expiring the host name.

But what does the 2820 application do? Does it recognise changes in WAN IP address and make smart choices or does it just send out blind and dumb forced updates every "Auto-Update interval" period? If so that is a really stupid and almost useless design, where a user must choose an interval which is intended to be sufficiently frequent to promptly notify changes in WAN IP address assignment but not so frequent that DynDNS suspends the account for abuse from excessive updates. And AFAIK, there is no such value which can do both of those.

BTW, is there any way to "nail down" two LAN hosts to each of the two WANs so that the LAN hosts can run sensible DynDNS clients (such as the very nice ones from Kana Solutions with a built-in email feature) for just their one assigned WAN?

Thanks for any advice.

Tony

After some experimentation, to get my desired domains onto the right WAN link, I set WAN1 as 'First' domain and WAN2 as 'Only' domain, that seemed to ensure that things stick.

I've got the update interval as 10 days (default) and not had a problem with expiry or refreshing, but I can't help with how the 2820 client actually works

Thanks for the comments. I set one host name to WAN1 only and another to WAN2 only and that works fine in binding them. My need if for reliable inward access to servers at an unattended site and I believe using your settings could cause the site to become "lost" for up to ten days after changes in IP addresses. I'm now on an Auto-Update interval of 15 minutes and hope DynDNS don't find that abusive. It's a pity DrayTech did not just do this right and then get it certified at https://www.dyndns.com/support/clients/hardware/.

BTW I believe the default is just 1440 minutes (1 day) and it is the maximum which is 14400 minutes (10 Days).

Tony