Re: nmap not scanning networks?

From: David Gilbert (dgilbert_at_dclg.ca)
Date: 06/18/04

  • Next message: Jason DiCioccio: "Re: ttyv for local only?" 
    Date: Fri, 18 Jun 2004 10:54:47 -0400
To: Zoran Kolic <kolicz@eunet.yu>

    >>>>> "Zoran" == Zoran Kolic <kolicz@eunet.yu> writes:

    >> nmap -sT -p 21 '172.19.17.*'
    Zoran> Have you tried without "'"? Or 172.19.17.1-254? Nmap works
    Zoran> for me. Maybe port 21?

    I've noticed that nmap on FreeBSD is particularly lame at scanning the
    local network. If the majority of the addresses on the local network
    are unoccupied, then it will pause with a 'no buffer space available'
    message and pause for 15 or 20 seconds each. This seems to be due to
    it wanting to send a number of packets to the same addresses and when
    the arp is not resolved we're putting a negative entry in the routing
    table.

    ... or at least that was the behaviour. Recent -CURRENTS don't even
    seem to try to send arp entries as the arp table isn't full of
    incomplete entries as it was before.

    Dave. 

    -- 
============================================================================
|David Gilbert, Independent Contractor.       | Two things can only be     |
|Mail:       dave@daveg.ca                    |  equal if and only if they |
|http://daveg.ca                              |   are precisely opposite.  |
=========================================================GLO================
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  • Next message: Jason DiCioccio: "Re: ttyv for local only?"

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