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a basic subnetting question

Discussion in 'Networks' started by kobem, Sep 29, 2007.

  1. kobem

    kobem Megabyte Poster

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    i have enough knowledge about subnetting but there is something stopped my mind

    as an example , think you own only one 192.168.0.0 network address in addition
    there are two routers connected to each other and each router has hosts

    router a ------ router b

    router a
    |
    |
    |
    |
    |
    host

    router b
    |
    |
    |
    |
    host


    according to the schema AND WITHOUT SUBNETTING and due to only one 192.168.0.0 what should we do ?

    would be one 192.168.0.0 between routers , other between router a and hosts ?

    or if we put 192.168.0.0 between router a and router b , don't we have any other network address to put?


    i know the subnetting state ; maybe we can use 192.168.0.0 /27 then 27-24 = 3 bit
    after that 111 192+64+32 = 224 256-224 = 32 block size 192.168.0.0 192.168.0.32 and so on ....
     
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  2. JonnyMX

    JonnyMX Petabyte Poster

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    What exactly are you trying to do?

    That doesn't read like a question...
     
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  3. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    The whole point of a router is to connect *different* networks. If you only have one network available then either ditch the routers for switches, or subnet to create multiple networks.

    Harry.
     
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  4. BosonMichael
    Highly Decorated Member Award

    BosonMichael Yottabyte Poster

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    This isn't a basic subnetting question if you have to perform the task (as you put in all caps and in bold) WITHOUT SUBNETTING.
     
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  5. kobem

    kobem Megabyte Poster

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    sorry perhaps i will simplify the question

    think the schema i gave on my first post

    there is only one network address (192.168.0.0) so

    WITHOUT SUBNETTING , according to the schema there are 3 networks

    one of them is between router a and router b 1.

    "]the other is between router a and host a 2.[/COLOR]

    last one is between router b and host b 3.

    my question : (WITHOUT SUBNETTING) if we have only one network address(192.168.0.0) ,
    COULD WE USE THIS UNIQUE NETWORK ADDRESS ONLY BETWEEN router and router b or router a and host a or router b and host b ?
     
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  6. stuPeas

    stuPeas Megabyte Poster

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    You do realise that routers have an address too?
     
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  7. kobem

    kobem Megabyte Poster

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    no you didn't understand

    i say that there is 192.168.0.0 and it is only one network address i have

    but there are 3 networks so if i use 192.168.0.0 , i consume all network address and will not be able to
    give any other addresses for other 2 networks yeah ?
     
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  8. Fergal1982

    Fergal1982 Petabyte Poster

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    ok... Im confused.

    What little I understand about Subnetting and IP allocation, etc exists as follows.

    As I understand it, the last octect in an IP address always identifies the individual machine so on a network my machine would be 192.168.0.1, yours would be 192.168.0.2, etc. No two devices on the network can contain the same IP. Other wise you will encounter lots of difficulties for communication. In this case, the example of subnetting you gave in your first post doesnt work.

    If you mean you only have the single range (192.168.0.xxx), then I believe you "could" theoretically have all the machines on your example setup running off the same range, without having to implement subnetting. That said, it depends on the number of machines. With a single range, you could only have 254 possible devices on the network (including the routers, servers, pcs, etc). So if you have 200 machines on 1 network, and 100 on the other, then no, you cant implement a continuous network without implementing subnetting.

    I always figure subnetting like a geographical location personally. In a large company (such as my last work), each physical office location used a different subnet. This allowed them to have up to 254 devices in the office (any more, and another subnet needed to be assigned to the office and configured). It makes life a hell of a lot easier for a start. For instance, if you know machine 192.168.0.12 attempted to access a machine at a certain time, you have no idea where it is. Using subnetting allows you to narrow it down a bit ("oh, its on x subnet, thats in new york!").

    I could, of course, be wrong in what ive said. After all, Networking isnt really my area. If thats the case, someone else will be along to correct what ive said.
     
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  9. stuPeas

    stuPeas Megabyte Poster

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    I'm sorry Kobem mate but i think you need to go back and read about IP addresses again. You would not be in a position where you only had one address. Indeed the address 192.168.0.0 IS a NETWORK address and NOT an individual MACHINE/DEVICE address. If you have the Network address 192,168.0.0 available to you, then you have the addresses 192.168.0.1--192.168.254.254 available FOR MACHINES on your network. That is A LOT of IP ADDRESSES you CAN use for the machines on your network.

    It is the last 2 octets (ie the 0.0) that you use to create subnets.
     
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  10. kobem

    kobem Megabyte Poster

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    you do not still understand , i do not mention machine ip addresses (interface ip addresses)

    i know how to subnet but pay attention here " if we don't use subnetting "and we just possess
    192.168.0.0 but have 3 networks

    so that if i allocate this for one of the 3 networks , what could i give for other 2 networks?
     
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  11. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    You could use parts of 10.0.0.0 or 172.16.0.0

    Harry.
     
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  12. kobem

    kobem Megabyte Poster

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    but i have only one network address and it is 192.168.0.0 and i can't use the addresses you mentioned.

    i have to show the picture for you to comprehend

    [​IMG]

    perhaps you understand this
     
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  13. stuPeas

    stuPeas Megabyte Poster

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    Then WITHOUT SUBNETTING ( as far as I know and Im no expert). It CANNOT be done matey. Is this a question from a book or assignment? If it is, can you post the question? :D
     
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  14. stuPeas

    stuPeas Megabyte Poster

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    ANYONE can use these addresses. They are for private use by an individual or company.
     
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  15. ffreeloader

    ffreeloader Terabyte Poster

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    Well, once again it's very obvious that you haven't begun to study the basics of a subject. Here's a news flash for you Kobem. You break up 192.168.0.0 into subnets. Now, I've told you what you have to do, now go figure out how to do it. Study the basics. That's what they are there for.
     
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  16. MacAllan

    MacAllan Byte Poster

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    I think this is a question for god - as with only one address and without subnetting, to create three networks is a problem god alone knows how to solve...
     
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  17. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    The the only thing you can do is to effectively turn the routers into switches, if they will allow you to do this. Most domestic routers won't allow this, but I can imaging top end routers can be got to route on MAC address. Or you might be able to route on single IPs, but it would be a nightmare to admin.

    Otherwise I'd replace the routers with switches.

    Harry.
     
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  18. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    Er - <cough> - Kobem has made it fairly plain that the restriction is one *network* address.

    Harry.
     
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  19. kobem

    kobem Megabyte Poster

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    after consuming the 192.168.0.0 to assign network 1 ,

    network 2 >>> ? 192.168.0.0 ?

    network 3 >>> ? 192.168.0.0 ?
     
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  20. ffreeloader

    ffreeloader Terabyte Poster

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    [​IMG][​IMG][​IMG]
     
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