Broadcast listener

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This topic contains 6 replies, has 5 voices, and was last updated by Avatar theterranaut 13 years, 5 months ago.

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    Jonathan80
    Member
    #116991

    Hi

    How can I listen / view all broadcasting in my lan?
    Do you know a utility for that? (google found only 1 obsolete program which didn’t work ‘DHCP Broadcast listener 1.0’)

    thanks

    Avatar
    yaniv
    Member
    #224154

    Re: Broadcast listener

    http://www.ethereal.com/ is a very strong packet analizer.

    you can filter things that you dont need to see… very good for lan trouble shooting

    Avatar
    Jonathan80
    Member
    #281626

    Re: Broadcast listener

    Thanks.
    Do you have any idea what should I filter in order to see broadcasts only?

    Avatar
    theterranaut
    Member
    #285798

    Re: Broadcast listener

    I haven’t Ethereal on this machine, but anything with a destination of 255.255.255.255 (or all FF’s) is what you would be looking for.

    theterranaut

    Avatar
    daviddavis
    Member
    #263631

    Re: Broadcast listener

    You should be able to run Ethereal for a while then stop capturing. Next, sort it by destination IP address.

    Broadcasts will look like either 255.255.255.255 (all hosts on all networks) or directed broadcasts like 192.168.1.255 (all hosts on the 192.168.1.x network).

    By sorting them, they will be all together and you can then look at the source IP’s.

    Let us know if you have any trouble.

    Thanks,
    David

    JeremyW
    JeremyW
    Moderator
    #267926

    Re: Broadcast listener

    Should we note that the broadcast address will be different than 255 if you have a netmask of /25 or higher (i.e. 255.255.255.128 or higher)?

    e.g. 1
    Network address = 192.168.1.0
    Netmask = 255.255.255.128
    Broadcast address = 192.168.1.127

    e.g. 2
    Network address = 192.168.1.0
    Netmask = 255.255.255.192
    Broadcast address = 192.168.1.63

    Avatar
    theterranaut
    Member
    #285805

    Re: Broadcast listener

    Jeremy, David-

    of course, quite correct.

    Apologies for any confusion caused, I was thinking of a (very) broad example.

    theterranaut

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