2 Seperate SBS 2003 servers in ONE switch?

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    Mintel
    Member
    #115674

    Dear all,

    I recently had a conflict with my boss regarding a order we just recently got in.
    I will explain what all the fuss was about :beer:

    The case:

    We just got a customer that wants to place there servers in our server room.
    In total 3 servers. Domain controller, Terminal server and a SQL/middelware server.
    So my collegae of the sales department and I had the idea to seperate, physicaly, there network from the ours.

    So they have there own 3COM Gigabit switch and so have we. Each Switch connects to its own NIC interface of our Firewall en from there they are connected to the internet. The firewall will make sure that each network doesn’t see the other.

    Ok, this will work, right?

    But now, the cheap ass (my boss) wants it cut down the costs by ruling out the extra switch by putting… you never want to believe it, in the same (!!) switch as ours.

    So in that situation, we have the following.

    2 SBS 2003 servers, 2 Terminal servers en a few more servers.

    I told my boss, that that was a “absolutly no-no”

    It was simply not possible to put 2 DHCP servers in 1 switch. Ok, that is true he said. But what if we switched off 1 DHCP of a domain controller and put the customers network in static IP’s in a totally another IP range. Get it?

    So i thought, and thought, and rememberd a ex-collegae telling me that it was simply not possible the place 2 SBS 2003 servers in 1 switch, because Microsoft built in a fail-safe to prevent that.

    Is this true? And can anyone give feedback on this issue. Is my boss right? Is it possible (i personally think not ofcourse :) ) or am i right? And why?

    Thanx in advance guys :)

    Forgive me if this is a big no-no question. But any help is granted :)

    Ciao,

    David
    The Netherlands

    Avatar
    Dumber
    Participant
    #195853

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    AFAIK it’s possible to run multiple SBS servers, as long there are seperated domains.
    However, in case of security, i don’t know if it is a recommodation.

    Avatar
    teiger
    Member
    #228823

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    As long as there is only one DHCP in any collision domain it will work as planned. However tell your boss that the cost of administering Static IP addresses, keeping an up to date list of them, configuring any laptops that come in, and any lost productivity because some smart alec configures his own machine to be the same IP as the default gateway or firewall, will all outweigh the cost of an extra switch in a few months.
    I remember back in the days of DOS when we were in an Enterprise outfit and we needed to add a TCP/IP stack for FTP, everyone was issued with their own diskette with their IP address and host file on it. One guy said my FTP doesn’t work and the guy in the next dept copies his own diskette for him and tells him to use that. Well the stations went crazy and none of them worked (unseen messages about duplicate IPs flooding the wire), it took the system people responsible about a day and a half to find the cause!!

    Avatar
    biggles77
    Spectator
    #204956

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    My apologies if I have missed something here, but why not VLAN the switch? You can then have 2 physical networks running throught he one switch with the appropriate DHCP ruuning for each SBS domain.

    Avatar
    teiger
    Member
    #228825

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    Cost of 2 simple switches vs. 1 switch which supports VLAN, maybe?

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    ahmer_sahab
    Member
    #285991

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    Hi,
    I m sure that u can implement vlans using 3 com giga byte switch. u have not put model number of your switch. i was thinking to search for the vlan configuration on 3 com web site but i wasn’t sure about ur switch model number.
    if u dont wanna create vlan . u can still use two dhcp server in one vlan. use both dhcp server to serve ur network. use one dhcp server to issue 80% of adderss and another one to issue 20% of addresses. this way the load would be balanced as well. if u r using domain enviroment, create seperate domain for ur dept and other one seperate.
    your scenario doesn’t looking it will give u ne prob
    u can solve ur prob by
    1- use vlan
    2- create seperate domain for the dept.
    if u cann’t create diffrent domain, then create OU for every dept computers and users. use group policy to provide privacy , security and software.
    3- use load sharing b/w ur infrastructure servers ( i dont mean load balancing)

    Avatar
    kojo1984
    Member
    #285015

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    Don’t use 2 SBS 2003 on one subnet… after 7 days great problem appear. One of these 2 SBS must be deactivated…

    Avatar
    teiger
    Member
    #228899

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    Not sure what you are referring to here.Also you don’t say if you mean same physical subnet or IP subnet. There is nothing in SBS being on the same subnet which will make it close down after 7 days. There IS a service which will close down the SBS DHCP service.

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    theterranaut
    Member
    #285857

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    Apologies for the late post.

    You could get around the problem of 2 DHCP servers on 1 subnet by:

    i)dividing up your address pool carefully
    ii)applying one half to one SBS box, the other on the other one
    iii)using DHCP class id’s on the server and the appropriate group of
    workstations to tell them what IP’s to pick up.

    theterranaut

    Avatar
    teiger
    Member
    #228977

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    This may be true for Win2K3 but not for SBS. If SBS detects another DHCP server on the network, it will close down. Period. Unless you hack the registry of course ;>)

    Avatar
    Tons of Fun
    Member
    #285666

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    What is the problem with putting 2 seperate networks on a single switch? I know that it’s not optimum and there might be bandwidth issues, and possibly some increased latency, but I thought that you could have 2 DHCP servers on a single switch as long as they were seperate domains.

    To qualify myself, I have installed 2 SBS 2003 networks in a typical single network fashion, so I am a beginner with SBS. I am studying for the SBS specialist cert and am working towards gaining experiance with SBS. I would like to know if there is a problem doing this so I don’t make any mistakes in the future.

    Thanks,

    JeremyW
    JeremyW
    Moderator
    #268349

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    If you have two DHCP servers in the same broadcast domain and they are handing out addresses to different subnets then you may (probably) get a client on the wrong subnet. This is because the client will take the IP lease from the server that responds first.

    If the switch has vlan capabilities then you can have two DHCP servers on the same switch with no issue if you separate the networks into two different broadcast domains.

    You can also have two DHCP servers in the same broadcast domain for fault tolerance.

    Avatar
    theterranaut
    Member
    #285860

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    Does it? I didn’t know that. I suppose it makes sense from an MS standpoint: limit the environment in which this box can be deployed. Bloody hell. Why am I not surprised?

    http://www.wehuberconsultingllc.com/wordpress/?m=200411

    (Adding a router/wap to my network

    Posted by Bill on 25th November 2004)

    thanks for the info, tieger

    theterranaut

    Avatar
    teiger
    Member
    #228982

    Re: 2 Seperate SBS 2003 servers in ONE switch?

    http://support.microsoft.com/kb/177610
    Not exactly a new problem….

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