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  • Troubleshoot slow networks

    I am looking for a solution to get a more in depth picture of a network.
    I want to see wich computer is creating alot of traffic or why the network is slow on certain moments.

    In general situation there is no manageable switch, so no port monitoring available.

    What i am thinking of is to buy a switch, wich i could use to troubleshoot this kind of situations, like slow network troughput. Wich i to be honest never encoutered before.

    I was looking for some appliance, wich could tell me the problem, but the problem is there is so many of them, i can't tell the difference anymore.

    My question to you people is, what is the best affordable way to troubleshoot slow networks.

    Environments excist of Windows servers and desktops, HP switches, etc.
    Standard IP v4, no errors in the event log, but still some weird slow network issues.

  • #2
    Re: Troubleshoot slow networks

    What kind of HP switches are those? I didn't know HP made unmanaged switches.

    The basic feature set that you want from a switch to be able to do what you're after is SNMP. sflow/netflow would be nice too. Stick with the bigger brands and you won't be disappointed. ProCurve, Cisco, Juniper, etc. Cheaper devices, while offering some manageability, might let you down such as low end NetGear and LinkSys models (although, IMO anything with the brand name LinkSys on it is low-end).

    From there you can either use free tools to get the SNMP/sflow info out of the switch of purchase a higher grade software tool like Whatsup Gold to pull the info out. A nice, cheap solution might be to use GroundWork Enterprise Quick Start for a few dollars which allows for monitoring up to 100 devices with plenty of good info available for analysis.
    Wesley David
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    • #3
      Re: Troubleshoot slow networks

      Get a crappy old HUB (so it "absorbs" ALL the network traffic ), a free Linux app that will do the monitoring and plug it into the network. Wireshark should do what you want.
      1 1 was a racehorse.
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      • #4
        Re: Troubleshoot slow networks

        Originally posted by biggles77 View Post
        Get a crappy old HUB (so it "absorbs" ALL the network traffic ), a free Linux app that will do the monitoring and plug it into the network. Wireshark should do what you want.
        Just to clarify, Iznogoud, you'd have to unplug all of the cables from the switch and plug them into the hub for this to work to be able to sniff all of your network's traffic.
        Wesley David
        LinkedIn | Careers 2.0
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        Microsoft Certifications: MCSE 2003 | MCSA:Messaging 2003 | MCITP:EA, SA, EST | MCTS: a'plenty | MCDST
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        • #5
          Re: Troubleshoot slow networks

          Originally posted by Nonapeptide View Post
          Just to clarify, Iznogoud, you'd have to unplug all of the cables from the switch and plug them into the hub for this to work to be able to sniff all of your network's traffic.
          Um no. You just need the Server plugged into the Hub then the Hub to the Switch with the Sniffer hanging off the Hub.

          Remember a Hub send to every ports because it is stupid where as a switch wll send to the appropriate MAC address/port since it is smart.

          Obviously not ideal if you have a gigabit network since the Hub will slow it all down substantially.

          Click image for larger version

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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

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          • #6
            Re: Troubleshoot slow networks

            I think our confusion here is that I had the impression that he wanted to inspect the entire network's traffic as a whole, not just traffic to one server. In the OP he mentions "I am looking for a solution to get a more in depth picture of a network. I want to see wich computer is creating alot of traffic or why the network is slow on certain moments." That's why I initially thought your suggestion of a hub qould require him to plug everything into it if he wanted to view the entire network's traffic patterns.

            Did I make sense? It's hard to tell these days. 15 hour workdays do strange things to a person... ::twitch twitch::
            Last edited by Nonapeptide; 9th April 2010, 04:05.
            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
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            • #7
              Re: Troubleshoot slow networks

              Ok then, how about this. As mentioned above, it will slow the network speed down. I'm sure there has to be a better way than what I have suggested. This is just so old school.
              Click image for larger version

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              2 2 was 1 2.
              1 1 1 1 race 1 day,
              2 2 1 1 2

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              • #8
                Re: Troubleshoot slow networks

                That won't catch traffic between ports on a single switch, though
                Tom Jones
                MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
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                IT Trainer / Consultant
                Ossian Ltd
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