Nonsense. You already have something that copies the hosts file to every host. It does that check as a product of copying the hosts file. rsync is old, and even before that we had rcp!
What you don't have, and have never had, is the ability to check all of your recursive resolvers from every machine and easily compare the results. rsh might've failed for other reasons that you have to check first. Nameservers might be ok, but ethernet hub might be broken. Might be temporary. Might be an active cache poisoning attack. Might be out of ports. You just don't know. DNS is always a moving target. A huge amount of energy is put into building monitoring and recording the results of monitoring and looking back on previous observations, and it's still not perfect: nagios can say everything is okay, and still service was down. Sometimes you never find out why.
A better way to think about it is: push don't poll. You know when the master hosts file changes and you know how long it takes to push it to all the machines. Polling the DNS servers just in case it changes is silly.
> The entire Internet uses DNS for billions of hosts. To say it won't work for a tiny internal network seems a bit strange.
Ok. Then look at it this way. A DNS server effectively has to look at its own hosts file and publish the results in response to online queries.
Assuming the failure rate of getting answers from a hosts file is constant, why exactly do you think those online requests have a negative failure rate? That’s what would be required for DNS to beat hosts files!
If we’re talking about different networks then the hosts files do not have the same failure rate, and that’s the first time DNS (or something like it) could be better.
> DNS isn't "new" at this point. I remember configuring old SunOS boxes in the 90's, switching them from NIS to DNS. Exciting times.
Confessions from the cargo cult. Oh well. Hopefully the above makes it clear why this was a mistake.
If not, I’m not sure what else to say. In 1996 I was converting sunos boxes at that time back to hosts files and yp because the failure rate of DNS was higher and the previous guy left. What else could I do? If I’d told my boss we needed to keep using DNS because “it works for the Internet” I would’ve gotten laughed at. We had real work to do!
Your time would've been better spent fixing your DNS servers, adding a second one for redundancy. If you told me you couldn't make DNS work in 1996, I would've laughed, figured you were just inexperienced. If you told me you couldn't make it work today, I'd ask HR to get the paperwork ready.
What you don't have, and have never had, is the ability to check all of your recursive resolvers from every machine and easily compare the results. rsh might've failed for other reasons that you have to check first. Nameservers might be ok, but ethernet hub might be broken. Might be temporary. Might be an active cache poisoning attack. Might be out of ports. You just don't know. DNS is always a moving target. A huge amount of energy is put into building monitoring and recording the results of monitoring and looking back on previous observations, and it's still not perfect: nagios can say everything is okay, and still service was down. Sometimes you never find out why.
A better way to think about it is: push don't poll. You know when the master hosts file changes and you know how long it takes to push it to all the machines. Polling the DNS servers just in case it changes is silly.