hi
just thought to give a basic explanation of propogation time...
actually dns prorogation depends on SOA parameters.
not all dns host allow u to modify ur soa parameters......but some do :)
it is Start Of Authority
Refresh in SOA parameter tells the slave nameservers when to chk the master nameserver for any update.
now e.g if ur refresh parameter is 3600 seconds...
and now u just change a dns record........instantly when u change SOA serial no. increases
nowe.g if u open/hit ur site in less then one hr.......then itdepends........in case u hit Primary server, u will see the new recordbut in case u hit slave servers then u might see the oldrecords.........
and which dns server u hit depends on MANY reasons like
- which one is nearer....sometime anycast technology is also used
- which one has less load
- which one is accessible in less hopes in the route via ur ISP
but since refresh time is 1hr (in this example...) then u WILL see all changes just after 1hr !!!
somy recomendation to "people in hurry" is better to decrease refreshparameter in SOA to about 1-5mins (chk the minimum ur dns hostsupports...)
and then do all changes..........and when see allwrking fine after 3-4 days increase those values so as to minimizeresource wasteage :)
Hope that will be benificial :)