none
Sometimes some web sites don't open at first try RRS feed

  • Question

  • I'm not sure where to put this question, because I don't know what system is causing this.

    I have a customer who had a very slow internet connection, and one thing that was frustrating was that sometimes some sites did not load at first try, as if the browser didn't find it, or (another symptom) only loaded the most basic HTML code. A refresh solved this. Please note that this happened say one fifth of the times a site was accessed, and it appeared randomly, as far as I know. It is the same for all users and it happens from all computers on the LAN.

    Last week we installed fiber and everybody's happy that surfing the web is much faster, but unfortunately this weird non-loading of some sites sometimes still applies.

    It seems to me that it is some DNS issue, but at the same time, DNS resolution works, so...

    The environment is a very small Active Directory domain, where the internal DNS has forwarders to 8.8.8.8 and the ISP's DNS. The router is a D-Link DSR-250N, which in turn has the same DNS configuration.

    I cannot find anything in the router that would affect this, to the best of my knowledge; there are simply no rules that affect web surfing.

    While looking into this last week, I tried different external DNS servers, etcetera, while clearing the DNS cache on the server, flushing caches at servers and clients, restarted the router, and so on and so forth; but nothing really changes regarding this phenomenon.

    Also, note that the customer had one ISP last week, and now another, with a different gateway and so forth.

    If anybody has an idea what may causing this, I would be very happy if you shared it.



    Monday, March 14, 2016 10:05 AM

Answers

  • Thank you both for your feedback, I appreciate that you took the time! The symptoms experienced led us all in the wrong direction, however. Extensive googling eventually led me to what seems to be the solution: Disable setting "Block UDP Flood" in the router...! 
    Tuesday, March 15, 2016 2:31 PM

All replies

  • I believe you need start analyzing from client side,

    1. While opening the Website, Run (netstat or netstat -no 2 ) command and see if you are getting IP addresses which is not acessible (SYNSENT) or TIMEWAIT, Once you have those IP's you can investigate from those IP's.

    To troubleshoot further,

    1. Telnet to the destination website IP address with port number,

    2. Also run, Network monitoring software's, to see if you can find some errors.

    3. Create a host entry file for Website, (If possible bypass that IP address from Proxy to check)

    4. Run http watch (Third part app) on client desktop and check, it will provide you some detailed information to troubleshoot.


    Regards,
    Manjunath Sullad

    Monday, March 14, 2016 11:34 AM
  • Hi Jazzmanvibration,

    Please try Manjunath's suggestions,and you also could check following points:

    1.Connect the web sites with IP address,does it have same problem?

    2.Check the firewall or 3rd-party softwares on your DNS servers.

    3.Try to connect internet directly with static IP DNS,without firewall router/switch,a laptop will be good,test again.

      Best Regards,

    Cartman

    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Tuesday, March 15, 2016 4:06 AM
  • Thank you both for your feedback, I appreciate that you took the time! The symptoms experienced led us all in the wrong direction, however. Extensive googling eventually led me to what seems to be the solution: Disable setting "Block UDP Flood" in the router...! 
    Tuesday, March 15, 2016 2:31 PM