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how are they able to detect my IP address?

Discussion in 'Networks' started by kobem, Oct 31, 2007.

  1. kobem

    kobem Megabyte Poster

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    for instance i signed up for a forum like this and wrote an article that is unwanted i mean
    thats omitting the rules of that forum site . And think they had a prosecution , attempted
    to punish me


    how can they detect my IP address?

    cause my public IP changes as i reset my dsl modem , can they find it in ISP records?
     
    Certifications: CCNA
  2. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    Basicaly - yes.

    The IP address will be in all the packets you send.

    In the UK - if the Police need to trace a connection they ask the ISP to say what account was using that IP address at that time. The ISP will have the info in their RADIUS logs.

    Harry.
     
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  3. kobem

    kobem Megabyte Poster

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    yeah i recalled the packet event (destination , source IP fields and other fields)

    but my public IP changes as i reset my modem so that assume they detected
    my ip for example 88.2.3.4

    but later i shut my PC then opened again MY IP changed(consider it is not a static IP)

    so ? there is no such IP belong to me ?
     
    Certifications: CCNA
  4. greenbrucelee
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    greenbrucelee Zettabyte Poster

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    You mean your IP is APIPA?
     
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  5. kobem

    kobem Megabyte Poster

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    didn't understand what you mentioned but i am telling about my PUBLIC IP to go for internet
     
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  6. BosonMichael
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    BosonMichael Yottabyte Poster

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    Just because you reset your modem doesn't mean you're definitely going to get a different IP address. If you're still within your DHCP lease period, the DHCP server will likely renew your old lease.

    Besides, what Harry said is correct; your IP information is logged by the ISP. If you've done something you shouldn't have, then it can be discovered.
     
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  7. greenbrucelee
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    greenbrucelee Zettabyte Poster

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    if your IP is not static then its APIPA meaning it changes.

    APIPA is set bu default in windows and if your DHCP server can not find your IP address then it gets one assigned and it should start with 169.
     
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  8. BosonMichael
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    BosonMichael Yottabyte Poster

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    Actually, if your IP address is not static, it is not necessarily APIPA; it is dynamic. If a DHCP server is available, it will get the address information from the DHCP server. If a DHCP server is not available, a Windows device will assign itself an APIPA address.

    Dynamic addresses don't necessarily change every time. You could very well get the same address multiple times in a row with DHCP. You lease an address from a DHCP server for a period of time. If you leave your computer off for longer than the lease duration, you might (or might not) pick up a different address.
     
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  9. greenbrucelee
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    greenbrucelee Zettabyte Poster

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    HAvent learned about dynamic yet :oops:
     
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  10. BosonMichael
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    BosonMichael Yottabyte Poster

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    Both APIPA and DHCP are dynamic. But to be honest, APIPA is pretty useless.
     
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  11. kobem

    kobem Megabyte Poster

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    for instance i looked for it from command console and lease duration is an hour!

    think i shut my pc for two hours , my IP will change or not change
    in this way , let's assume it changed and applying the omitting rules of forum example ,


    can they detect me? cause my IP changed!
     
    Certifications: CCNA
  12. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    Yes - because your username will be in the ISP's RADIUS logs, along with the new IP address.

    Harry.
     
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  13. greenbrucelee
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    greenbrucelee Zettabyte Poster

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    This has been answered, your ISP will have the new IP the forum can cantact the ISP to get the new one any that have just been assigned to you.
     
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  14. greenbrucelee
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    greenbrucelee Zettabyte Poster

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    Think of it this way.

    If I was to upset people on here and I got banned, and my IP had changed I couldn't rejoin under a different name because the powers that be would know it was me.
     
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  15. Mr.Cheeks

    Mr.Cheeks 1st ever Gold Member! Gold Member

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    Kobem,

    There will be two DHCP servers in this instance.
    1. The first on on your modem/router, which will have a lease time for 1hour for example.
    2. A DHCP server that is manager by your ISP, which probably has a lease time of 2 weeks for example.

    say your ip address is 174.164.15.131 and you shut down your machine for 3 hours, and log back on, and the ip address is still 174.164.15.131, this is becuase your lease has not expired for the DHCP server that is managed by your ISP.

    Remember,
    your ip address 174.164.15.131, is your WAN address which is managed by your ISP.
    your ip address 192.168.1.10, is your local ip address which is managed by your modem/router

    As mentioned before, if your WAN ip address (174.164.15.131) did change your ISP can find out all of your previous ip address that were allocated to yourself.
    Each time you log into a forum, just like this one, it stores your ip address on their records, and if you log under 2 separete usernames here and do some "dodgy" business, then, both user names will be assigned to that 1 ip address, as the ip address has not changed (unless you use an Anonymous (sp) proxy server)

    Does this make sense?
     
  16. kobem

    kobem Megabyte Poster

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    ah yeah , also my new IP is assigned by them ! ok man i got it
     
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  17. kobem

    kobem Megabyte Poster

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    you said "your ip address 192.168.1.10, is your local ip address which is managed by your modem/router"


    but there are two local addresses , one of them is ethernet interface of pc and other is
    ethernet interface of modem

    and here you said

    "
    There will be two DHCP servers in this instance.
    1. The first on on your modem/router, which will have a lease time for 1hour for example.
    2. A DHCP server that is manager by your ISP, which probably has a lease time of 2 weeks for example.

    "

    simultaneously two dhcp servers?
     
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  18. BosonMichael
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    BosonMichael Yottabyte Poster

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    Your ISP assigns a public address to the external interface of your modem... and your modem assigns an internal address to your PC. So, yes, there are essentially two DHCP servers.

    The internal Ethernet interface of your modem will have a static address. The address assigned to your PC will be on the same subnet as the internal interface of your modem so they can talk to each other.

    For the record... all this stuff is covered in that Network+ book we advised that you study... 8)
     
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  19. BosonMichael
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    BosonMichael Yottabyte Poster

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    As Harry said, yes, your ISP still knows who you are based on the hardware address of your modem.

    If the lease given to your modem is a one hour lease, and you shut the modem for two hours, then it might pick up a new address... or you might get the original address... it often depends on whether another device on that network is assigned your original address or not.

    The DHCP lease process is also covered in detail on the Network+ exam... thus, why we recommended it to you.
     
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  20. Bluerinse
    Honorary Member

    Bluerinse Exabyte Poster

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    In reality i very much doubt that your ISP would release any information at all relating to your IP lease logs from their RADIUS server, to admins of an Internet forum.

    ISPs would only release this information to authorised people in the legal system ie the courts, police etc.

    So, you are most likely covered by a data protection act. though you will not be protected if your activities are deemed to be illegal.
     
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