<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
<font face="Arial"></font>Hi<br>
<br>
The problem was that "reverse-path filtering" was enabled. after
disabling reverse-path filtering I could receive broadcasts as
expected.<br>
<br>
As a side note - interface does not need to be in promiscuous mode<br>
<br>
cheers pieter<br>
<br>
On 13/07/2011 10:03, Pieter wrote:
<blockquote cite="mid:4E1D513F.9030405@vastech.co.za" type="cite">Hi
All
<br>
<br>
Im running Linux 2.6.32.14 on an embedded MPC4858.
<br>
One of the Application (CLI) must reciece a UDP broadcast packet.
<br>
<br>
The problem is that I only receive packets broadcast from within
the same subnet (192.168.0.x) even though the broadcast app
sends the broadcast to 255.255.255.255.
<br>
<br>
when i run tcpdump on the embedded machine it shows both
broadcasts from the same subnet well as different subsets: as
shown below:
<br>
<br>
SDH-0A000221> /tmp/tcpdump port 23 or port 33334
<br>
tcpdump: verbose output suppressed, use -v or -vv for full
protocol decode
<br>
listening on eth0, link-type EN10MB (Ethernet), capture size
65535 bytes
<br>
(1) 07:48:35.787826 IP 172.16.63.184.cli >
255.255.255.255.cli: UDP, length 58
<br>
(2) 07:48:43.832539 IP 192.168.0.1.cli > 255.255.255.255.cli:
UDP, length 60
<br>
(3) 07:48:43.840627 IP 192.168.0.254.cli > 192.168.0.1.cli:
UDP, length 112
<br>
<br>
The embedded machine is configured with:
<br>
ip 192.168.0.254
<br>
mask 255.255.0.0
<br>
<br>
(1) is a broadcast from a different subnet
<br>
(2) is broadcast from within same subnet
<br>
(3) the imbeded applications reply to the broadcast from same
subnet
<br>
<br>
<br>
The service has been delared in "etc/xinetd.d/cli" as follows:
<br>
service cli
<br>
{
<br>
socket_type = dgram
<br>
protocol = udp
<br>
port = 23
<br>
wait = yes
<br>
user = root
<br>
server = /usr/vastech/in.cli
<br>
disable = no
<br>
cps = 10 5
<br>
flags = IPv4
<br>
}
<br>
<br>
and the port assigned in "/etc/xinetd.d/services" as follows (port
23 for back comparability with older products)
<br>
<br>
#telnet 23/udp
<br>
cli 23/udp
<br>
cli 33334/udp
<br>
<br>
Is there something basic that I have overlooked ? should the
interface be set and left in
<br>
promiscuous mode to do what I require?
<br>
<br>
thanks pieter
<br>
<br>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
VASTech PTY (LTD)
021 880 9807</pre>
</body>
</html>