Announcement

Collapse
No announcement yet.

VLANs

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • VLANs

    Hello I'm new to the forum and pretty new to the IT industry. I'm seeking advice/ideas for possibly setting up VLANs at my job.

    Here is my situation... I work in a school and I am on site support, so I can do a few things but not much. I'm trying to increase the performance of our network and I'm not sure if VLANs would do just that. We have a full T1, and we are fully switched, but performance on our network is not very good during peak hours. There are a total of about 200 computers on the network, sometimes more depending on how many students are using the wireless.

    I have no administrative access to the Cisco 2600 router or the main switch. But I can configure most of the other Cisco 2950 switches any way I want. I haven't done much yet except set an IP address, default gateway, subnet mask, password, and save the settings. I have a total of 9 switches to configure. We have 4 lab rooms with 30 PCs in each one, and the last room is a library with 20 PCs.

    My question is...should I setup a VLAN for each lab or is that just too much? If I can, will I be able to without administrative rights on the router or main switch? Any help would be greatly appreciated.

  • #2
    Re: VLANs

    I would start monitoring what traffic passes during the peak hours...
    And what is slow? File transfer? Opening a word file on a file server? Internet?
    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: VLANs

      Internet is slow.

      Is it a good idea to seperate each lab with a VLAN?

      Comment


      • #4
        Re: VLANs

        Internet is slow means absolutely nothing. If you have a 56k connection it will be slow. If you have twin ADSL 2+ connections and it is still slow it will mean something different. Please quantify any statements like that.

        Packet shaping might be a better option if you want to apply equal bandwidth to all Labs/users.
        1 1 was a racehorse.
        2 2 was 1 2.
        1 1 1 1 race 1 day,
        2 2 1 1 2

        Comment


        • #5
          Re: VLANs

          Please do not start creating vlans if you don't know where you up to!!
          Daviddavis can tell you all about it, but afaik you need some kind of routing devices between each vlan. You problably need to resubnet also. So wait with that!!!

          If you're internet is slow, tell me/us more about you're connection. What is slow???? Which protocol? HTTP or also FTP? Do you have a proxy server/firewall? Whats the performance on those machines? How much diskspace do they have left? How thick is you're line to the internet? How did you setup DNS resolving? What happens with a traceroute? etcetcetc.

          If filetransfers running great to you're fileserver there may not be needed to create vlans.

          The only advantage is that you break the broadcast domains. You can monitor if you have problems with broadcasts? Sure VLans are great, but not always needed.
          See here for info about VLANS.
          http://en.wikipedia.org/wiki/VLAN

          Also make a Layer 2 drawing of you're network and place it here.
          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: VLANs

            Hi eenglish34,

            further to all thats been said already, another thing to consider is:

            If 'internet access speeds' are your problem, you may want to consider some measures like the below-

            -defining, creating, then policing policies for internet access (always involves input from management and/or faculty!)

            -and/or a proxy that can do caching. ISA2004 is absolutely spot on for this kind of thing, but there are others (I like ISA's AD tie-in, if you are using AD.)


            Basically you want to get faculty buy-in on an acceptable use policy, let the users know whats /whats not acceptable, , install a device that can police and log this for you, and ensure those that have the power to do so come down like a ton of bricks on abusers. A proxy should also be able to tell you the kinds and amounts of traffic traversing your internet connection.

            my 0.02p!

            regards and good luck!

            theterranaut

            Comment


            • #7
              Re: VLANs

              hi there,

              As u said , u do not have access to routers. then creating Vlan would put u in another problem. If u create vlans then for communication b/w vlan u need to use router. As u said u dont have access to routers so u wont b able to put communication b/w vlans.
              In order to check why ur network is slow. if ur network consist of Windows computer then u can use performance utility present in Administrative tool. u also need to make sure that ur network is slow due to downloading speed from ISP or ur internal users are downloading large files or it could be due to internal computers broadcast or it could be due to slow processing speed of computers.
              There r several counters available on performance tool to monitor performance of the systems. Check the hardware, internet usage and internal network trafic to find the bottle neck.

              Comment


              • #8
                Re: VLANs

                I appreciate everyone's responses. I just had a simple question and believe me I'm not going to create a VLAN if I haven't tested and retested it first. I was just curious. I'm just looking for any way I can to improve our network, that's all. We do have an acceptable use policy but of course no one abides by the rules and they just use proxy sites to bypass the firewall. Thanks again for all the help/suggestions.
                Last edited by eenglish34; 4th November 2006, 21:08.

                Comment


                • #9
                  Re: VLANs

                  One of my customers is a highschool - 1400 studentsa and about 200 computers. We had the same problems. The problem is not with file sharing or central storage, it's Internet - that's what highschool kid do.

                  The school had an 8 Mb DSL HAS account going into a Forticate 60 appliance. The Fortigate has dual WAN inputs so we added another 8 Mb DSL account and set up bandwidth allocation.

                  That's was our solution. Incidently, a T1 isn't that fast anymore. We have a 143 Mb OC3 feeding a schoolboard up here with 60 schools. We have a VLAN created using a combination of wireless and DSL.
                  Network Engineers do IT under the desk

                  Comment


                  • #10
                    Re: VLANs

                    Hi Eric,
                    Thanks for your post!!!!
                    For VLANs to connect to each other, they need a router inbetween them. It sounds like you don't have access to the router at your site, then it could be pretty tough to create VLAN's. You could, however, put in your own router, I suppose.
                    So, you have a main router, you could then connect to another router that had an 8 port ethernet adaptor with downlinks to each classroom. Put a switch at each classroom and make each classroom a VLAN.
                    Will this help your slow internet speed? Hmm, doubtful... Didn't you all put in a Packeteer? That was suppose to slow down stuff like downloads, streaming video/audio, and speed up web browsing. What is your bandwidth utilization and circuit size?
                    Talk to you later,
                    David
                    David Davis - Petri Forums Moderator & Video Training Author
                    Train Signal - The Global Leader in IT Video Training
                    TrainSignalTraining.com - Free IT Training Products
                    Personal Websites: HappyRouter.com & VMwareVideos.com

                    Comment

                    Working...
                    X