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  • Rather Slow Internet

    Synopsis:
    Client network consists of a number of mixed-OS workstations and laptops (around 10, iirc) and an SBS 2003 server. I can replicate the problem on the server, trying to load google.com takes about 25 seconds - mostly it says "waiting for..."

    Internet access while browsing is VERY slow. Ping responses to google etc are quick enough and snappy enough. Monitoring traffic on the router shows very low utilisation.

    DNS has been reviewed, Dbug logs were enabled, and showed very quick, snappy lookup times from the openDNS forwarder.
    DNS Cache has been cleared out, and server restarted.
    There is no Proxy server, and no proxy configured.

    Client is really quite annoyed. Any suggestions on what I can do ? I've also checked for excessive TCP/UDP connections on the server, and NAT sessions on the router, all look ok. There are no unusual processes or TCP connections on the server.



    I've been doing some more research on it this morning and found following:
    Two network adaptors, one is a 3c905, in a disabled state, with NLB bound and enabled.
    THe other is a Broadcom NeteXtreme, also with NLB Bound and enabled.
    It doesn't look fully normal to me - it errors in the event log saying "WLBS cluster mode cannot be enabled due to parameter errors. All traffic will be passed to TCPIP.

    Could this be relating to me problem at all? I want to disable it, but that won't be able to happen till this evening, as I'm fairly sure it'll need a reboot.

    I've got Netmon 3.4 downloaded, and will do some captures soon.
    I've also got MBAM about to run, just for sureties sake.

    So, help me out fellows
    anything at all - even making sure the power is at the correct frequency :P
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  • #2
    Re: Rather Slow Internet

    As for the network card that is bound to SBS, I'd disable all bells and whistles. I know that SBS 2008 doesn't do so well with things like offloading enabled. Apparently it's not even a supported configuration to run SBS 2008 with TCP offloading. For example, on my SBS 2008 box, the following was disabled for my HP NIC:

    Code:
    Large Send Offload (IPv4)
    Large Send Offload v2 (IPv4)
    Large Send Offload v2 (IPv6)
    Receive Side Scaling
    TCP/UDP Checksum Offload (IPv4)
    TCP/UDP Checksum Offload (IPv6)


    Also, the following was disabled at a netsh prompt

    Code:
    netsh int set global autotuning=disabled
    netsh int set global congestion=none
    netsh int set global chimney=disabled
    netsh int set global res=disabled
    All of that was disabled at the prompting of a MSFT support guy when I was having some terrible DNS issues with the server. Perhaps that has something to do with it? Of course, update the drivers to their latest incarnation as well. Make a backup first!! =)
    Wesley David
    LinkedIn | Careers 2.0
    -------------------------------
    Microsoft Certifications: MCSE 2003 | MCSA:Messaging 2003 | MCITP:EA, SA, EST | MCTS: a'plenty | MCDST
    Vendor Neutral Certifications: CWNA
    Blog: www.TheNubbyAdmin.com || Twitter: @Nonapeptide || GTalk, Reader and Google+: [email protected] || Skype: Wesley.Nonapeptide
    Goofy kitten avatar photo from Troy Snow: flickr.com/photos/troysnow/

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    • #3
      Re: Rather Slow Internet

      Create a sniffer trace.
      And is NLB enabled on a single host?
      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"

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      • #4
        Re: Rather Slow Internet

        yes, nlb on a single host. theres no other server.
        I've got a netmon cap i'm going to try and understand tomorrow.

        Ill have a look for all those xtra options nonapeptide pointed out too
        Please do show your appreciation to those who assist you by leaving Rep Point https://www.petri.com/forums/core/im.../icon_beer.gif

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        • #5
          Re: Rather Slow Internet

          import it in wireshark.. its a bit easier to read.

          And NLB on a single host? remove it. it has no use and it's only overhead.
          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


          • #6
            Re: Rather Slow Internet

            Have you tried using a different DNS? You said you checked yours out, can you just point to a public DNS?

            Have you tried browsing via IP? Remove DNS completely and try to access 66.102.11.104?

            I am assuming that you have checked the settings on the router and at the ISP (you sure your not on dail up :P )?

            Why are you not using all the NICs in the server? Anyhow, can you try changing the NIC's.

            I am thinking that its a problem on the server, can you get a laptop and plug stright into the modem? Then move it back a step at a time. At the very lest it will pin point the location of the error (Modem, Router, Server, Network cables).

            Let us know what the Netmon says.

            Also, have you run a few tracesrt's to make sure the isp has not f'ed there routing up (Ie, does it take more then 11 hopes to get to google (depending on the area you live in)).

            Last but not lest, Get a Hammer and Sit it next to the router/switch and tell the router/switch to behave... Its worked for me before.

            Wofen
            Good to be back....

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            • #7
              Re: Rather Slow Internet

              yea, we've checked the router, we've checked with the isp, they say there are no problems.
              i've watched nat sessions on the router, traffic flow monitor on the router, it's all fairly normal.

              interestingly, the client computers don't transmit via the server, they just use it for dns, but experience the same problem. on a new day, this is starting to make me think maybe i shouldn't be worrying about things on the server, especially when dns-debug showed lookups taking microseconds more or less


              I don't have site access, so playing with network cards isn't optional, and the 2nd card i mentioned shouldn't be there apparently.

              today's my last day on it i think, if i can't get something useful from the capture, i'm going to escalate it and be done

              \\i might also see if we can send a replacement modem, as that's the only other common item
              Last edited by tehcamel; 27th October 2010, 08:25.
              Please do show your appreciation to those who assist you by leaving Rep Point https://www.petri.com/forums/core/im.../icon_beer.gif

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              • #8
                Re: Rather Slow Internet

                Moved to SBS2003 forum
                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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                • #9
                  Re: Rather Slow Internet

                  ok so my netmon capture reported heaps of crap, including "acknowledgement for packet not in sequence" or something like that

                  I'm going to get some switch, cable and router gear replaced to test it out.
                  Please do show your appreciation to those who assist you by leaving Rep Point https://www.petri.com/forums/core/im.../icon_beer.gif

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                  • #10
                    Re: Rather Slow Internet

                    What kind of internet connection is it? DSL? Can you try to switch from PPPoE to PPPoA or vice versa? Had an issue here in the states with a terrible connection and random website blockage and the ISP recommended to change from oA to oE (or was it vice versa?) and it worked. I had someone explain to me what they thought was the culprit behind it, but totally forgot.
                    Wesley David
                    LinkedIn | Careers 2.0
                    -------------------------------
                    Microsoft Certifications: MCSE 2003 | MCSA:Messaging 2003 | MCITP:EA, SA, EST | MCTS: a'plenty | MCDST
                    Vendor Neutral Certifications: CWNA
                    Blog: www.TheNubbyAdmin.com || Twitter: @Nonapeptide || GTalk, Reader and Google+: [email protected] || Skype: Wesley.Nonapeptide
                    Goofy kitten avatar photo from Troy Snow: flickr.com/photos/troysnow/

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