nmap not scanning networks?

[David Gilbert]

>>>>> "Zoran" == Zoran Kolic <kolicz at 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 at daveg.ca                    |  equal if and only if they |
|http://daveg.ca                              |   are precisely opposite.  |
=========================================================GLO================