How the cache works?

[Len Conrad]

>I have a question, about the caching and proagating of DNS zones. Whats
>happen if i have a domain in the internet and i change an IP address of
>one of my hosts that are under my domain, how longs does this change
>reflects on the DNS across the world.

the immediately next query will see the new value, except for queries for 
that record that are ansered from cached for TTL period by other name servers.

>I mean how long takes to change the cached records of the DNS on internet

TTL

Len


http://MenAndMice.com/DNS-training
http://BIND8NT.MEIway.com : ISC BIND 8.2.3 "NT3" for NT4 & W2K
http://IMGate.MEIway.com  : Build free, hi-perf, anti-abuse mail gateways