Hi:
I realize this question may not be fedora specific but here it is.
I am trying to determine how soon after a
/sbin/ifconfig eth2 up 192.168.0.2
can I actually successfully send UDP packets out that interface. (UDP
since i wanted to keep things simple, not TCP flow/congestion control
entanglements.) I have a loop such as:
#!/usr/bin/perl -w
$utime = $ARGV[0];
while(1) {
system "usleep $utime";
system "/sbin/ifconfig eth2 down";
system "date";
print "after eth2 down\n";
system "usleep $utime";
system "/sbin/ifconfig eth2 up 192.168.0.2";
system "date";
print "after eth2 up\n";
}
From my tests it appears that it takes between 4 to 6 seconds after the
"up" command before my UDP packets actually start going out. The tests
are between two machines with addresses 192.168.0.2 <---> 192.168.0.3.
Any hints welcome. The "/sbin/ifconfig eth2 up 192.168.0.2" command
returns right away, but the interface is not ready to go for a few
seconds. What can this be due to?
Gautam
