DNS Resolving Issue

[TravG]

I noticed my one website www.onlineslotshub.com was not working properly, I would get a resolve_err using Google Chrome when I tried to open it. It would work when I typed in the IP address however.

So I called GoDaddy and they said the DNS was not resolving correctly, so he had me change my name servers and then change them back saying that would force the service providers to reset my DNS and the website would start to resolve correctly. It has not worked yet, but I am wondering how much this affects my website. Some people around the world cannot obviously see the website so I am not getting visitors. He said it was not a GoDaddy issue but i have never heard of this happening before on any of my other websites. When I looked to see how the website was functioning around the world, about half of the locations had errors.

So I am wondering if there is anything I can do to make sure this doesn't happen again. Also, is this something that happens from time to time and does it normally fix itself? Had I not looked at my website who knows how long this would have went on.

[TheGooner]

It's (probably) a chrome problem just local to your machine.
If you can get to the website using another browser on that machine (Firefox, IE, Edge) then it is the case.

BACKGROUND :
Chrome records how it gets to various Ip addresses in a wee file that it stores on your PC - and if it goes back to an IP address it has visited before it tries to take the same route. If one of the servers or links is down on that route then Chrome bounces back with an error.

FIXES :
In Windows 7 you can simply visit the website using another browser - and that shows Chrome how to get there (usually).

If that doesn't work (or you are using Windows 10) then you can fix it by flushing your ipconfig ... like this.

1/ Right click on your windows icon (bottom left hand corner)
2/ Choose command prompt. This brings up a DOS box
3/ When the box appears then type in IPCONFIG /FLUSHDNS

This drops all the routing information - so Chrome does not take the old path - and finds the new way to get to the website.



SUMMARY :
If it works - then it was never a problem with your website or your host or your ISP.
It's a problem with Chrome and was fixed by flushing out old IP information on your PC / Laptop.

(This happens to me down here relatively frequently - about once a week).

[universal4]

Great tip on the dns flush, in fact I have a server application that used to have trouble resolving dns once in a while so I wrote a bat file that does that and run it every 60 seconds so every single dns lookup is forced to a top level dns server to resolve the name.

During my original research (I know this will sound wrong and it took some time but it WAS the findings I found) the issue mostly came about since some dns resolvers use anycast for their recursive lookups. (anycast allows a list of public recursive dns servers to be queried) and quite often when Google dns server was queried they came up with the WRONG ANSWER.

I did find that Google was wrong more on .co.uk names then others, but once I saw those results I removed Google from the list of dns servers queried, as well as a specific server I was using at the time that used anycast with Google in the list, and changed to Level 3 servers and the problem went away.

If anyone ever sees this kind of issue on a consistent basis you may find that your isp is using Google or some other dns resolver that is prone to a poisoned cache, or some other issue with their lookups.

I was never able to prove why Google was wrong with it's lookups, but I made sure I never used them for recursives again and really do not have the time to see if they ever fixed the problem. (I suspect it still exists)

Paul, in your case if it happens as often as you say you could consider a windows task that runs every so often and a schedule that fits within your normal work schedule.

Rick
Universal4

[TheGooner]

I think the reason it happens so often down here is that many of that paths from New Zealand to websites are quite long-winded and many of the jumps in the path are quite temperamental ... it regularly takes 34-40 hops to get from my ISP to a website ...

This page gives a good summary of Chrome and the cache ...
http://www.howtogeek.com/197804/how-...he-on-windows/

And a cool comand to type into chrome ...
chrome://net-internals/#dns

Fascinating to see how this all hangs together

[universal4]

Thanks for that link Gooner, I had never read that in depth about Chromes internal cache and see that as a flaw with their browser.

If any other browser CAN find the site and Chrome doesn't that helps back up the theory Google's browser is flawed.

Gooner, have you ever tried setting your machine (or home router) dns to something other than your isp dns to see if the problem happens less?

Of course if Chrome is gonna cache a lookup and not check with authoritative dns servers when a path is not found, I would think using a browser that successfully finds websites a higher percentage of the time makes more sense.

Rick
Universal4