How run IpDiscover ?
First (and usual), IpDiscover could run from agent.
They could only do a discovery on their local network !
(lots of things about election to chose an agent and not another, are described in the link you've supplied)
(be carefull of the size of the local network : /16 means 65534-1 ping !!)
Second, IpDiscover could run from Server, using the supplied (perl) script 'ipdiscover-util.pl'.
IMHO use of this script need to provide all parameters needed like '-h', '-d', '-u' and '-p' as the script put data inside the database.
The script supplied with 2.9 version is well designed with parameters :
(line 66) :
for $option (@ARGV){
if($option=~/-a$/){
$analyse = 1;
}elsif($option=~/-auto$/){
$auto = 1;
}elsif($option=~/-cache$/){
$cache = 1;
$analyse = 1;
$xml = 1;
}elsif($option=~/-path=(\S*)$/){
$path = $1;
}elsif($option=~/-ipdiscover=(\d+)$/){
$ipdiscover = 1;
$ipd = $1;
}elsif($option=~/-xml$/){
$xml = 1;
....
