[Elecraft] Has this link been changed?

David Woolley forums at david-woolley.me.uk
Sun Dec 29 11:34:44 EST 2013


DNS changes don't propagate.  However the results of DNS searches do get 
cached.  In principle, when you make a request, the request is routed to 
the name server for the domain in question, and to get there, requests 
may have to be made for higher level name servers, up to the root level. 
  In practice, requests are normally made through the ISPs caching name 
server, so, if someone else has accessed the name recently, the query 
will be satisfied from there.  That means that very few requests ever 
get sent to the root level servers, but the .COM ones may still be quite 
busy.

DNS entries have a lifetime associated with them, and cached entries 
which are older than that lifetime are ignored, and the request 
forwarded towards the definitive server.

A competent system administrator will reduce the lifetime down to 
minutes, a day or two before making any planned change, so that the 
change will take effect very quickly.

-- 
David Woolley
Registered owner K2 06123

On 29/12/13 03:47, Fred Jensen wrote:

>
> The link on your desktop is simply a URL.  All that works in the
> Internet are IP addresses.  There is a translation between URL's and
> real IP addresses, it happens in the Domain Name Servers around the
> world.  An update used to come out once a day, don't know now, but the
> DNS talk to each other and the update propagates around the world.
>



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