On Fri, Jan 13, 2006 at 04:10:21PM +1300, Christopher Sawtell wrote: > > Is this a wrapper for dns? > No. It replaces the public DNS system.
Well, it doesn't so much "replace the public DNS" as say "you don't have to use the public DNS for this class of machines ..." The general idea seems to be pretty specific - I don't think I've come across any of the problems they list ... > Public DNS servers regularly fail due to overloading and system > administration problems. I guess he means that "public dynamic DNS servers" fail. Haven't noticed dyndns failing, but I've only used it for the last 2 years ... The real DNS is very heavily replicated, and hasn't been seen to fail overall. > There is no notification when a system goes online. Instead you must > poll DNS regularly to see when a system comes online. True - DNS is not a real-time notification system. Some people need one, so DNS isn't adequate. No news there ... > Updating can take from several minutes to several hours before the > change is made public. On systems with small idle timeouts it is often > impossible to find the current IP address via DNS. Not sure what they mean here ... I guess in extreme cases DHCP could be revoking leases faster than your dynamic DNS updates go through, but that's an example of a stupid setup. Also, some crap ISPs have been found to totally ignore the TTL on DNS zones, and just cache things for a week anyway. > Public DNS services only keep track of the current address and don't > record past times or changes in a central location. Very true. They're not supposed to :-) -jim
