discovering the ip address of a device - TCP-IP

This is a discussion on discovering the ip address of a device - TCP-IP ; Hi I have to discover the ip address of the network interface of a dumb embedded system. I can connect to the device directly with an ethernet cable. But which tool can force the device to communicate its address? If ...

+ Reply to Thread
Results 1 to 9 of 9

Thread: discovering the ip address of a device

  1. discovering the ip address of a device

    Hi

    I have to discover the ip address of the network interface of a dumb
    embedded system.

    I can connect to the device directly with an ethernet cable.

    But which tool can force the device to communicate its address?

    If the device remains silent, simply listening with tcpdump will not help.
    Arping will not help either.
    Nmap or some other port scanning tool could help in theory, but portmapping
    can take an indefinite time, as they would have to scan any address (256 **
    4 combinations)

    Actually, in the ethernet protocol specifications, is there any command that
    force a device to answer?

    thanks in advance

  2. Re: discovering the ip address of a device

    noop wrote:

    >Hi
    >
    >I have to discover the ip address of the network interface of a dumb
    >embedded system.
    >
    >I can connect to the device directly with an ethernet cable.


    If you can connect to the device, with a PC I'm guessing?? Then the pc
    has an IP address and the device must be on the same ip range.. So
    you can get a little program that will do a search of all the ip
    addresses in that range and give you the ip addresses of the devices
    that it finds..


    >But which tool can force the device to communicate its address?
    >
    >If the device remains silent, simply listening with tcpdump will not help.
    >Arping will not help either.
    >Nmap or some other port scanning tool could help in theory, but portmapping
    >can take an indefinite time, as they would have to scan any address (256 **
    >4 combinations)
    >
    >Actually, in the ethernet protocol specifications, is there any command that
    >force a device to answer?
    >
    >thanks in advance



  3. Re: discovering the ip address of a device

    In article <44e77f70.47662994@news.eclipse.net>,
    njkat@eclipse.net (gene martinez) wrote:

    > noop wrote:
    >
    > >Hi
    > >
    > >I have to discover the ip address of the network interface of a dumb
    > >embedded system.
    > >
    > >I can connect to the device directly with an ethernet cable.

    >
    > If you can connect to the device, with a PC I'm guessing??


    I think he meant that he can *physically* connect it to the PC, not that
    he can establish a connection with an application.

    If the device doesn't use DHCP to initialize its IP address, I'd expect
    the manufacturer to have hard-coded an IP address. The documentation of
    the device should say what IP address it uses, so there shouldn't be any
    need to discover it.

    But if you can't find out, I'd suggest that you simply try pinging every
    address in the range 192.168.0.1 through 192.168.255.254.

    --
    Barry Margolin, barmar@alum.mit.edu
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***
    *** PLEASE don't copy me on replies, I'll read them in the group ***

  4. Re: discovering the ip address of a device

    Saturday 19 August 2006 23:29, Barry Margolin showed some signs of brain
    activity:

    > In article <44e77f70.47662994@news.eclipse.net>,
    > njkat@eclipse.net (gene martinez) wrote:
    >
    >> noop wrote:
    >>
    >> >Hi
    >> >
    >> >I have to discover the ip address of the network interface of a dumb
    >> >embedded system.
    >> >
    >> >I can connect to the device directly with an ethernet cable.

    >>
    >> If you can connect to the device, with a PC I'm guessing??

    >
    > I think he meant that he can *physically* connect it to the PC, not that
    > he can establish a connection with an application.


    Yes sorry if I was not clear: I can plug a cable in the box.

    > If the device doesn't use DHCP to initialize its IP address, I'd expect
    > the manufacturer to have hard-coded an IP address. The documentation of
    > the device should say what IP address it uses, so there shouldn't be any
    > need to discover it.
    >
    > But if you can't find out, I'd suggest that you simply try pinging every
    > address in the range 192.168.0.1 through 192.168.255.254.
    >


    Yes.
    Or perhaps a broadcast ping.


  5. Re: discovering the ip address of a device

    "noop" wrote in message
    news:44e77bbe$0$5535$ba620e4c@news.skynet.be...
    > Hi
    >
    > I have to discover the ip address of the network interface of a dumb
    > embedded system.
    >
    > I can connect to the device directly with an ethernet cable.
    >
    > But which tool can force the device to communicate its address?
    >
    > If the device remains silent, simply listening with tcpdump will not help.
    > Arping will not help either.
    > Nmap or some other port scanning tool could help in theory, but
    > portmapping
    > can take an indefinite time, as they would have to scan any address (256
    > **
    > 4 combinations)
    >
    > Actually, in the ethernet protocol specifications, is there any command
    > that
    > force a device to answer?
    >
    > thanks in advance


    A couple things I'd try. Using a packet sniffer (such as tcpdump) is part
    way there. Try doing it while booting the device up. Most IP based
    products will send out an arp packet when booting up to make sure that the
    address is not in use. You most likely will see that, or perhaps some
    dhcp/bootp packets.

    Next, you can try to set a static arp on your pc for that device and then
    try to connect. Some devices will respond, most will not. But, it is worth
    a try.

    Hope that helps,

    Jim



  6. Re: discovering the ip address of a device


    noop wrote:
    > Hi
    >
    > I have to discover the ip address of the network interface of a dumb
    > embedded system.

    --
    >
    > Actually, in the ethernet protocol specifications, is there any command that
    > force a device to answer?


    This is a common scenario. A device is attached to a network and we
    dont know its IP address. Barry has already mentioned that the easiest
    way is to just check the manuals. There are no mechanisms in Ethernet
    or IP to force a response. The broadcast ping method (sending a normal
    ping to the broadcast address *.255) usually does not work because an
    ICMP echo requests for broadcasts may be "silently discarded". UPnP
    (Universal Plug and Play) usually comes to the rescue in these cases.

    What type of device are we talking about ?

    If your device supports UPnP - it will periodically advertise its
    service via SSDP messages on the broadcast address, you can pick it up
    with a network analyzer. Alternately, you can add a UPnP Control Point
    such as Windows XP to the network. This will send out SSDP Discover
    messages to force all UPnP devices to respond. You can then check using
    a network analyzer or via "My Network Places".

    If your device does not support UPnP and is otherwise silent, then you
    need to check the manuals or run a ping scan.


    Vivek Rajan
    http://www.unleashnetworks.com


  7. Re: discovering the ip address of a device


    "VivekRajan" wrote in message
    news:1156048650.467484.299840@m73g2000cwd.googlegr oups.com...
    >
    > noop wrote:
    >> Hi
    >>
    >> I have to discover the ip address of the network interface of a dumb
    >> embedded system.


    > What type of device are we talking about ?


    Fair question. You have to specify the type of the device in order to get
    better help.

    The Dude



  8. Re: discovering the ip address of a device

    VivekRajan wrote:
    > The broadcast ping method (sending a normal
    > ping to the broadcast address *.255) usually does not work because an
    > ICMP echo requests for broadcasts may be "silently discarded". UPnP
    > (Universal Plug and Play) usually comes to the rescue in these cases.


    Usually not, but a good fraction of devices do.

    It is much easier than other ways, so it is probably worth trying.

    -- glen


  9. Re: discovering the ip address of a device

    In article ,
    glen herrmannsfeldt wrote:
    >VivekRajan wrote:
    >> The broadcast ping method (sending a normal
    >> ping to the broadcast address *.255) usually does not work because an
    >> ICMP echo requests for broadcasts may be "silently discarded". UPnP
    >> (Universal Plug and Play) usually comes to the rescue in these cases.


    >Usually not, but a good fraction of devices do.


    If I recall correctly, only two of my several peripherals support UPnP,
    and at least one of them is a firewall -- exactly the kind of device
    you do *not* want to be under control of the PC (not if you take
    you security at all seriously.)

    I routinely turn UPnP off "just in case". I haven't yet found a single
    instance in which it did anything useful for me.

    Now automatic device detection and driver setup on USB -- that has been
    convenient. But not, in my experience, UPnP.

+ Reply to Thread