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  1. Senior Member boxerboy1168's Avatar
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    #1

    Default ARP broadcast on a Cisco switch?

    Can I send out a broadcast on a switch to collect all the currently connected MAC addresses?? If so what's the command?

    Thanks.

    I tried Googling it but it's hard to find a direct answer.
    Currently enrolling into WGU's IT - Security Program. Working on LPIC (1,2,3) and CCNA (and S) as long term goals and preparing for the Security+ and A+ as short term goals.
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    #2
    The switch will pick up the Mac of connected devices as soon as it receives a packet from that Mac on that interface unless I'm missing something else?
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  4. Burn Baby Burn! Cisco Inferno's Avatar
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    #3
    could just ping sweep
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  5. Senior Member boxerboy1168's Avatar
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    #4
    ok thanks
    Currently enrolling into WGU's IT - Security Program. Working on LPIC (1,2,3) and CCNA (and S) as long term goals and preparing for the Security+ and A+ as short term goals.
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  6. Burn Baby Burn! Cisco Inferno's Avatar
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    #5
    Quote Originally Posted by boxerboy1168 View Post
    ok thanks

    yep, thats what I meant to say, which is sorta the same thing.

    One thing to remember is that the default mac address table (CAM Table) lifetime is 5 minutes. Thats why its not too significant.


    A host's MAC will not be flushed as long as it continuously sends and receives traffic. If a host has not sent or received any traffic within the duration of the aging time, it's MAC will be removed from the table.


    Devices and IPs change and things are moved around. You wouldnt want to wait a while for that to flush.
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    #6
    I think you can ping the broadcast address and get some hits on a Cisco switch, but it's pretty flaky from my experience. For example pinging 192.168.1.255 on the subnet 192.168.1.0/24.
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