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  • How to test connectivity

    I work in an office of approximately 25 PCs. About 5 of those are unable to reach certain intranet sites (internet works fine on all).

    I've released/renewed IPs, flushed DNS, disabled the FW, AV, did GPupdate, cleared cookies, temp files, made sure IE uses the same settings as the other PCs that can access those sites. Checked the ports on the switch by attaching a PC that can access those sites (it had no problems). Tried different browsers, tried accessing the site by its IP. I put the PCs in a workgroup, then back to our domain with a different computer name. I probably forgot to list some of my steps. All PCs are running on XP SP2 and have no malware of any kind. They are also the same model, configuration as the other machines.

    This might not even belong in this forum, but until I know what's causing this...well it is a connectivity issue.

    I'd appreciate any and all suggestions, detailed instructions as to what to do/check next. T

  • #2
    Re: How to test connectivity

    does ping works?
    Marcel
    Technical Consultant
    Netherlands
    http://www.phetios.com
    http://blog.nessus.nl

    MCITP(EA, SA), MCSA/E 2003:Security, CCNA, SNAF, DCUCI, CCSA/E/E+ (R60), VCP4/5, NCDA, NCIE - SAN, NCIE - BR, EMCPE
    "No matter how secure, there is always the human factor."

    "Enjoy life today, tomorrow may never come."
    "If you're going through hell, keep going. ~Winston Churchill"

    Comment


    • #3
      Re: How to test connectivity

      Yes, ping works just fine.

      Comment


      • #4
        Re: How to test connectivity

        Does the page require java or .net framework or anything of that sort? I'd compare the software installed on a machine that can connect with a machine that can't.

        Can you put up a static test page to see if that comes up?
        You also might want to use something like www.wireshark.org to see what's going on.
        Regards,
        Jeremy

        Network Consultant/Engineer
        Baltimore - Washington area and beyond
        www.gma-cpa.com

        Comment


        • #5
          Re: How to test connectivity

          Have you tried adding them to the Local Intranet site settings in IE?

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          1 1 was a racehorse.
          2 2 was 1 2.
          1 1 1 1 race 1 day,
          2 2 1 1 2

          Comment


          • #6
            Re: How to test connectivity

            @JeremyW: no the site doesn't require anything special. I can't replace the site, since it wasn't put there by me. It's a large company.

            I'm aware of Wireshark's existence and would gladly use it if I knew how to test the connectivity of a site. Care to provide some instructions?

            @biggles77: yes, I did try that. I actually lowered the settings all the way down an it doesn't make any difference.

            Comment


            • #7
              Re: How to test connectivity

              Originally posted by CypherBit View Post
              @JeremyW: no the site doesn't require anything special. I can't replace the site, since it wasn't put there by me. It's a large company.
              I was merely suggesting adding a static page, not replacing/deleting/adding a website.

              I'm aware of Wireshark's existence and would gladly use it if I knew how to test the connectivity of a site. Care to provide some instructions?
              You can start by taking a look at the http traffic. See if the server responds and what it's response is.

              Marcel or somebody else can probably give you some better tips. Whenever I analyze traffic I aways seem to be "feeling my way through".
              Regards,
              Jeremy

              Network Consultant/Engineer
              Baltimore - Washington area and beyond
              www.gma-cpa.com

              Comment


              • #8
                Re: How to test connectivity

                Use wireshark.
                Click interfaces, select the right one and click start.
                let him run.
                Now start do you're thing. When failed, stop Wireshark.

                Now create an expression. For example:
                ip.addr==10.0.0.5
                or
                ip.dst_host==10.0.0.6
                or
                src port http
                or
                dst port http
                Marcel
                Technical Consultant
                Netherlands
                http://www.phetios.com
                http://blog.nessus.nl

                MCITP(EA, SA), MCSA/E 2003:Security, CCNA, SNAF, DCUCI, CCSA/E/E+ (R60), VCP4/5, NCDA, NCIE - SAN, NCIE - BR, EMCPE
                "No matter how secure, there is always the human factor."

                "Enjoy life today, tomorrow may never come."
                "If you're going through hell, keep going. ~Winston Churchill"

                Comment


                • #9
                  Re: How to test connectivity

                  Thank you both, I really appreciate it.

                  I'll try my luck with Wireshark and report back in any case.

                  Comment


                  • #10
                    Re: How to test connectivity

                    I tried to gain additional information by running Wireshark, but didn't get much.

                    All the traffic from my IP to the site's seemed to be fine (that is based on my very limited experience with Wireshark; there were no strange colors).
                    I did get two checksum warnings from my IP to an IP that is unknown by me. This is a https site, so it might be checking for a cert or something.

                    I tried to ping that unknown IP from a PC that has full connectivity and also get no response, so it might be nothing.

                    Any additional suggestions are more then welcome (with or withouth the use of Wireshark). I just need to resolve this...somehow.

                    Comment


                    • #11
                      Re: How to test connectivity

                      Try a ping with the -a switch and see if it resolves. eg c:\>ping -a 10.123.123.xxx
                      1 1 was a racehorse.
                      2 2 was 1 2.
                      1 1 1 1 race 1 day,
                      2 2 1 1 2

                      Comment


                      • #12
                        Re: How to test connectivity

                        colors won't tell you anything!
                        you should look at requests and answers.
                        Also at the time when it took place.

                        Can't you test it on an other site which doesn't include SSL connectivity????
                        Marcel
                        Technical Consultant
                        Netherlands
                        http://www.phetios.com
                        http://blog.nessus.nl

                        MCITP(EA, SA), MCSA/E 2003:Security, CCNA, SNAF, DCUCI, CCSA/E/E+ (R60), VCP4/5, NCDA, NCIE - SAN, NCIE - BR, EMCPE
                        "No matter how secure, there is always the human factor."

                        "Enjoy life today, tomorrow may never come."
                        "If you're going through hell, keep going. ~Winston Churchill"

                        Comment

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