DYNDNS

[Lectrician]

I have several DYNDNS accounts for customers for various reasons, all are paid for ones, not the free ones (which expire unless you physically log in each month).

If the IP address changed, you would never be aware as the update was immediate and populated across the net quickly.

Recently in the last couple weeks I have noticed hosts go stale with an old IP address. When you log into DYNDNS to view the last update, you can see it has been updated and the IP address showing inthe control panel is current and working. It is the host name in the DNS records of the DNS server that are stale.

If I manually set the DNS server on my laptop to DYNDNS's own server, the host works perfectly. If I leave it set to my ISP's DNS servers, or use Googles 8.8.8.8/8.8.4.4 servers then it can takes DAYS before the host name resolves. Kind of pointless!

Anyone else noticing this recently?

I have a script on my server which runs automatically every 24hr and pings all the hosts and static IP's I look after, and emails me each 24hr with a nice green "OK", or a red "The following connections are not available" type message. I often get the red one!

 

[diyer56]

I suppose it depends on what the TTL is set to on the DYNDNS servers. This will set the 'expiry' time for your domain name on other DNS servers across the internet.

You can check the TTL for a domain using online tools such as:
http://www.nabber.org/projects/dnscheck/?domain=gov
(The TTL is shown in the Info section) and is the expiry time in seconds.

Perhaps DYNDNS have increased the TTL time for domains in order to reduce the load on their servers?

 

[Lectrician]

I think there must have been some glitches, as it is working perfectly again now, updates being pretty much instant on all host names.

The default TTL on VIP DYNDNS accounts is only 60seconds, to force proper lookups and not cached. You can alter this higher, but 60 is ideal.