Troubleshooting DNS

[jonathankonrad]

I've been having a strange issue lately since I installed an Amahi box. Every so often a website will appear to go offline. Sometimes it will report

DNS Error - Server cannot be found.

Or the page will just be blank

If I call a friend, or make a VPN connection to work, I can still access that website in an RDP session on a box over at work. SO the website is not down. But it appears down.

I believe it is a DNS issue. How can I verify this or troubleshoot it more effeciently so I know what to do next. It's happening a little more often now and it's getting frustrated. One particularily poor site is:

www.applytoeducation.com

Which is frustrated since I'm looking for work! Thanks.

[bigfoot65]

Not sure if this will help, but try the network troubleshooter (http://wiki.amahi.org/index.php/Network_troubleshooting). It may reveal something is not set up correctly.

[jonathankonrad]

That's a very good trouble shooter. In my case though, it went well for all 13 steps. No problem. I have to say, right now I have no problem getting around the net either. This is "normal". Then, all of a sudden it will fail with DNS errors.

When that happens, restarting the Amahi server doesn't help either. Odd. I am behind a strange ISP though and it may be the interaction between the way they shape traffic and this box. I'll report or ask more when I know more.

I wish there was a graphical program that I could run that would watch all of my traffic out of my home network and maybe two steps out into the Internet. Just to see where the packets are going or not going.

Thanks.

[jerryzak]

Just wondering...

Whose DNS servers are you using to resolve queries when the local (Amahi) DNS "goes down"?

Also...

1. If you install Webmin app, it will let you in a really easy way enter IPs for additional public DNS servers. Doing a quick search should yield quite a bunch that are open to the public for that very purpose. They might not be the fastest and might be overloaded but will provide some redundancy.

2. You can always "hard-wire" DNS configuration on your client machine. On windows that's usually done through changing adapter's properties for the Internet Protocol. Once you are at it why don't you manually set all those connection related settings (IP, netmask, gateway IP, and DNS servers) and than try to resolve that failed DNS query again. If it goes through... then its the Amahi...

[jerryzak]

Oh... one more thing... even though it does not happen often, it is possible for your router to hang, effectively killing your communication. You see that now and then... But its usually intermittent and sometimes hard to point to.

Which reminds me... a few years back I would loose Internet at nearly the same time every day. Bitched to Verizon (as it was their FiOS service) just to learn that it goes down for the whole bunch of people in my neighborhood. Eventually they dispatched a service crew -- apparently some piece of equipment was going bad and as the sun was coming from behind the buildings and heating the enclosure it would overheat.