Hi, Why don't you create a short lived (say 5 minutes) A record for target.example.com. Under normal circumstances both ns1 and ns2 will return 11.22.33.44
You can then create a script that monitors the internet connection of isp A. If that is down, it will update the A records for target.example.com to the secondary IP adress. Because your A record has a short timeout, downstream clients should pick up the new ip address relatively quickly. However you have to be aware that some ISP ignore such short lived A records and cache the resolved address for a longer period of time. Depending on your internet connection, I might consider offloading this burden to a hosting company. Jos On Mon, Nov 21, 2011 at 10:52 AM, Pandu Poluan <pa...@poluan.info> wrote: > Hello all, I'm in need of some suggestions. > > You see, I have 2 Internet connections with public IP addresses, let's > say ISP A 11.22.33.44 and ISP B 22.33.44.66 > > Now, I want outside parties trying to connect to "target.example.com" > by default resolves to 11.22.33.44, but if ISP A's connection goes > down for any reason, the DNS server will instead return "22.33.44.66". > > The nameserver itself will be located in the company, accessible from > the world via "ns1.example.com" = 11.22.33.44:53 or "ns2.example.com" > = 22.33.44.66:53. This allows the nameserver to monitor the state of > the connections to ISP A and ISP B. > > I've been perusing pages discussing BIND, and came to the conclusion > that BIND is incapable of doing that. > > Anyone can recommend me a DNS server that has such capability? Or how > to implement this ability with maybe Python or (*shivers*) Perl? > > Rgds, > -- > FdS Pandu E Poluan > ~ IT Optimizer ~ > > • LOPSA Member #15248 > • Blog : http://pepoluan.tumblr.com > • Linked-In : http://id.linkedin.com/in/pepoluan > >
