NAT question

Discussion in 'MCSE' started by arsham, Jul 1, 2009.

  1. arsham

    arsham Guest

    hello
    must i use private ip addresses in my entire network when i am using NAT or
    connection sharing?
    when i share m y internet connection, it automatically changes my lan
    adaptor settings to using private address like 192.168.0.1


    best regards
    Arsham


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    arsham, Jul 1, 2009
    #1
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  2. arsham

    Chris M Guest

    Broadly speaking the whole point of NAT is so that you don't need a
    public IP address for each of your internal machines.

    You don't *have* to use private IP addresses on the Internal network,
    but Internet Connection Sharing won't let you do it any other way. If
    you want to do something more elaborate than basic NAT with 192.168.0.x
    as your internal network, you'll need to use some other NAT routing
    software/hardware like RRAS.

    Chris.
     
    Chris M, Jul 1, 2009
    #2
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  3. arsham

    John R Guest

    Yes. Using NAT means that your internal private IP addresses are getting
    wrapped and sent out using a routable public IP address. This allows you to
    share a single (or maybe more) routable public IP address with multiple
    internal devices. That's just how it works.

    John R
     
    John R, Jul 1, 2009
    #3
  4. arsham

    JohnB Guest

    JohnB, Jul 1, 2009
    #4
  5. arsham

    John R Guest

    More importantly, that is how it works.

    Using NAT means that your internal private IP addresses are getting wrapped
    and sent out using a routable public IP address. This allows you to share a
    single (or maybe more) routable public IP address with multiple internal
    devices.

    By definition, ICS means you are sharing your connection. The 192.168.0.x
    subnet is private class C address space. The fact that it limits you to
    192.168.0 is not important, this subnet is enough for 254 devices. If you
    are sharing more than that, you should not be using ICS. Shoot, if you
    sharing more than 15 or 20 you should not be using ICS. If 192.168.0
    interferes with other private address space networks on your LAN, again, you
    should not be using ICS. ICS was designed for the home user with limited
    networking abilities to share a few computers with a single
    DSL/Cable/dial-up connection without configuring a router.

    Simply replacing ICS with a cable/dsl router will give you all the
    functionality you need to overcome any ICS issues you might have. If you
    insist on using dial-up, and your network is that complex, get an RRAS
    server.

    John R
     
    John R, Jul 1, 2009
    #5
  6. But you *should* use private IP Addresses on the Internal network, because
    if you don't, whichever non-private IP network you usurp for your use will
    be inaccessible to you on the public Internet -- because any traffic to that
    real public network will be stuck inside your private network.

    The fact is.. there's no good reason NOT to use private IP addresses behind
    a NAT router.


    --
    Lawrence Garvin, M.S., MCITP:EA, MCDBA
    Principal/CTO, Onsite Technology Solutions, Houston, Texas
    Microsoft MVP - Software Distribution (2005-2009)

    MS WSUS Website: http://www.microsoft.com/wsus
    My Websites: http://www.onsitechsolutions.com;
    http://wsusinfo.onsitechsolutions.com
    My MVP Profile: http://mvp.support.microsoft.com/profile/Lawrence.Garvin
     
    Lawrence Garvin [MVP], Jul 11, 2009
    #6
  7. arsham

    PAJ Guest

    In your opinion!
    I never use NAT. I have no need for it and cannot be bothered with the
    extra hassle in getting everything working with it.
    SIP works better without it and that is good enough reason for me.
     
    PAJ, Jul 11, 2009
    #7
  8. Then this conversation is pointless.. because you "never use NAT".

    The thread is about scenarios that DO use NAT.


    --
    Lawrence Garvin, M.S., MCITP:EA, MCDBA
    Principal/CTO, Onsite Technology Solutions, Houston, Texas
    Microsoft MVP - Software Distribution (2005-2009)

    MS WSUS Website: http://www.microsoft.com/wsus
    My MVP Profile: http://mvp.support.microsoft.com/profile/Lawrence.Garvin
     
    Lawrence Garvin [MVP], Jul 14, 2009
    #8
  9. arsham

    PAJ Guest

    No it was not! You brought a NAT router into it.

    The OP wrote:

    "must i use private ip addresses in my entire network when i am using
    NAT or
    connection sharing?
    when i share m y internet connection, it automatically changes my lan
    adaptor settings to using private address like 192.168.0.1"

    So follow the thread properly. There's a good boy.
     
    PAJ, Jul 14, 2009
    #9
  10. <sigh>... "connection sharing" employs NAT. "connection sharing" *requires*
    the use of private addresses.

    The *option* to use, or not use, private addresses does not apply to
    "connection sharing", it ONLY applies to NAT devices.

    Note, also, the subject of this thread: "NAT question".

    The condescension is unnecessary. Shame on me for feeding the trolls.



    --
    Lawrence Garvin, M.S., MCITP:EA, MCDBA
    Principal/CTO, Onsite Technology Solutions, Houston, Texas
    Microsoft MVP - Software Distribution (2005-2009)

    MS WSUS Website: http://www.microsoft.com/wsus
    My MVP Profile: http://mvp.support.microsoft.com/profile/Lawrence.Garvin
     
    Lawrence Garvin [MVP], Jul 15, 2009
    #10
  11. arsham

    PAJ Guest

    You had already used it in your first reply and continue to do so with
    the term <sigh> so stop being a pompous dipshit. It was humour. Fool!

    Resorting to the troll insult also shows you cannot win any argument.
    Pot, kettle, black. Now go back to your mommy.
     
    PAJ, Jul 15, 2009
    #11
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