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WWW and Domain A record responses (WAS: Pinging Issue!)

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  • WWW and Domain A record responses (WAS: Pinging Issue!)

    Hi All,

    I am having a problem with retrieving data from a site.

    When I ping the site in this format http:// www .--.com it pings ok, but when I ping it as --.com the ping times out.

    The IP addresses are different for each case. I did not realise that the above two formats would generate two different results until now.

    Any suggestions please?
    Last edited by Josh50; 8th June 2009, 10:58. Reason: Not sure that site should have been clickable.

  • #2
    Re: Pinging Issue!

    There is no rule that says www .xxx.com and xxx.com have to be the same site. The ping results will depend on the individual router/firewall settings.

    Which one do you need to access?
    Last edited by AndyJG247; 8th June 2009, 10:01. Reason: Not sure that site should have been clickable.
    Tom Jones
    MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
    PhD, MSc, FIAP, MIITT
    IT Trainer / Consultant
    Ossian Ltd
    Scotland

    ** Remember to give credit where credit is due and leave reputation points where appropriate **

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    • #3
      Re: Pinging Issue!

      I've changed the subject to make things a little easier for searches and I don't think we need to link directly to that site, even if it is as an example!
      cheers
      Andy

      Please read this before you post:


      Quis custodiet ipsos custodes?

      Comment


      • #4
        Re: Pinging Issue!

        Oops! Didn't even think of it as being a live site
        Tom Jones
        MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
        PhD, MSc, FIAP, MIITT
        IT Trainer / Consultant
        Ossian Ltd
        Scotland

        ** Remember to give credit where credit is due and leave reputation points where appropriate **

        Comment


        • #5
          Re: Pinging Issue!

          Originally posted by Ossian View Post
          Oops! Didn't even think of it as being a live site
          The site is not really called xxx.com - that was just the way I showed the format of the site, meaning that for instance why should www.yahoo.com ping but yahoo.com NOT ping?!

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          • #6
            Re: Pinging Issue!

            Originally posted by Ossian View Post
            There is no rule that says www .xxx.com and xxx.com have to be the same site. The ping results will depend on the individual router/firewall settings.

            Which one do you need to access?
            Well, it makes no difference whether I type xxx.com or www .--.com, both will bring up www .--.com which should be the case according to what I've been experiencing with most sites.
            Last edited by Josh50; 8th June 2009, 10:55. Reason: Correcting ambiguity

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            • #7
              Re: Pinging Issue!

              I know you were using xxx. com as an example, but www. xxx. com is a real, live site with inappropriate material in most environments

              Please edit your links in the two posts above
              Tom Jones
              MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
              PhD, MSc, FIAP, MIITT
              IT Trainer / Consultant
              Ossian Ltd
              Scotland

              ** Remember to give credit where credit is due and leave reputation points where appropriate **

              Comment


              • #8
                Re: WWW and Domain A record responses (WAS: Pinging Issue!)

                The issue is with what DNS records exists for the domains in question. For instance regarding Yahoo:

                Yahoo has 3 domain A records listed as :

                yahoo.com. A 209.191.93.53 [TTL=21600]
                yahoo.com. A 69.147.114.224 [TTL=21600]
                yahoo.com. A 209.131.36.159 [TTL=21600]


                Yahoo has one CNAME record for WWW listed as:

                www.yahoo.com. CNAME www.wa1.b.yahoo.com. [TTL=300]

                The www.wa1.b.yahoo.com CNAME record resolves to: 209.191.93.52

                This is why you get different results when you ping www.yahoo.com and yahoo.com. This is perfectly normal and acceptable. Some companies use A records for WWW, some use CNAME records for WWW, some have their DNS record for WWW point to the same ip address as their domain A record, some don't. Some don't have domain A records at all. It all depends on how their DNS has been set up. What can confuse the matter even more (in the case of Yahoo) is that the DNS records listed often point to clusters of servers so you can get a different result every time you ping either yahoo.com or www.yahoo.com.

                So, after having said all that, what is the problem you're having?

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                • #9
                  Re: WWW and Domain A record responses (WAS: Pinging Issue!)

                  joeqwerty,

                  Many thanks for the excellent explaination.

                  I am going to have to let you know the name of the site in question as it's absolutely crucial that I get this problem sorted, because my living depends on it.

                  The site is igindex.co.uk and sometimes the problem gets sorted on its own for a very short time and then it stops working again - by that I mean, sometimes I manage to use the options within the application successfully but most of the time it does not function properly -

                  Their support team has failed to pinpoint the problem and my ISP are absolutely useless. So I am stuck....

                  And I am not even sure if igindex.co.uk (193.30.41.10) pinged okay that would mean my application would work as it should do - I just assumed as I could not ping 193.30.41.10 that must have been the reason for the failure.

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                  • #10
                    Re: WWW and Domain A record responses (WAS: Pinging Issue!)

                    In this case the WWW record and the domain A record do in fact point to different ip addresses, so you're goint to get different results from each one. The igindex.co.uk domain also appears to have some issues with DNS as evidenced by the report from DNSStuff.com (see attached). So you may get sporadic results every time. What is the specific problem you are trying to resolve? You mentioned an application, do you have an application that needs to connect to igindex.co.uk?

                    Also, both the WWW CNAME record and the domain A record for igindex.co.uk have very low TTL's (5 minutes).
                    Attached Files

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                    • #11
                      Re: WWW and Domain A record responses (WAS: Pinging Issue!)

                      To be honest I am not sure how their application is written as I am only a client (user) of theirs.

                      What I do is I login to my account using their Web-based trading software on URL REMOVED by MODERATOR . The application provides and updates all prices for hundreds of stocks. It seems when I try to open a trading window, the window sometimes fails to communicate with the server so prices don't get updated. The application is very bity and each section appears to be getting its data from various servers whose IP addresses I have no way of knowing - on some sections it seems to poll the data which even makes it harder to understand - what sort of dumb establishment creates such a complex software environment I have problems to understand.

                      Sorry I can't be more specific than above. I wish I had a way of learning more about how their software was written or at least their support team could know better which they seem not.
                      Last edited by biggles77; 9th June 2009, 00:21. Reason: Removed URL

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                      • #12
                        Re: WWW and Domain A record responses (WAS: Pinging Issue!)

                        Probably the best you can do is to run a packet capture program on one of your computers, start a packet capture and then launch the program and go through the functions you described. After running the program you can look at the captured traffic and see if anything sticks out. Look for DNS queries and TCP connections to external addresses to try and find a pattern or something that doesn't look right. If you use Microsoft Network Monitor 3 you can view the time of day in the capture and correlate that to the time you perform each function in the program. If you have a function that doesn't work or times out or hangs up make note of the time and then look at the captured traffic for that time period to see if you see something.

                        http://www.microsoft.com/downloads/d...displaylang=en

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                        • #13
                          Re: WWW and Domain A record responses (WAS: Pinging Issue!)

                          Finally managed to sort out the problem today!

                          It was a malware causing it - very strange symptoms indeed as it only affected the application when I logged through ADSL and it worked ok with a dialup connection - I did not mention the latter part in my earlier posts as did not want to create more confusion! So as things turned out now the pinging of igindex.co.uk had nothing to do with the problem as it still won't ping!

                          It feels like having gone through a life-saving operation when you get your system back working as it should

                          Thanks to all those who responded to this thread ..

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