problem receiving udp broadcasts

problem receiving udp broadcasts

[Pieter]

Hi All

Im running Linux 2.6.32.14 on an embedded  MPC4858.
One of the Application (CLI) must reciece a UDP broadcast packet.

The problem is that I only receive packets broadcast from within the=20
same subnet  (192.168.0.x)  even though the broadcast app sends the=20
broadcast to  255.255.255.255.

when i run tcpdump on the embedded machine it shows both broadcasts from =

the same subnet well as different subsets: as shown below:

     SDH-0A000221> /tmp/tcpdump port 23 or port 33334
     tcpdump: verbose output suppressed, use -v or -vv for full protocol =

decode
     listening on eth0, link-type EN10MB (Ethernet), capture size 65535=20
bytes
(1)    07:48:35.787826 IP 172.16.63.184.cli > 255.255.255.255.cli: UDP,=20
length 58
(2)   07:48:43.832539 IP 192.168.0.1.cli > 255.255.255.255.cli: UDP,=20
length 60
(3)    07:48:43.840627 IP 192.168.0.254.cli > 192.168.0.1.cli: UDP,=20
length 112

The embedded machine is configured with:
ip 192.168.0.254
mask 255.255.0.0

(1) is a broadcast from a different subnet
(2) is broadcast from within same subnet
(3) the imbeded applications reply to the broadcast from same subnet


The service has been delared in  "etc/xinetd.d/cli" as follows:
service cli
{
     socket_type        =3D dgram
     protocol        =3D udp
     port            =3D 23
     wait            =3D yes
     user            =3D root
     server            =3D /usr/vastech/in.cli
     disable            =3D no
     cps                =3D 10 5
     flags            =3D IPv4
}

and the port assigned in "/etc/xinetd.d/services" as follows (port 23=20
for back comparability with older products)

     #telnet        23/udp
     cli                23/udp
     cli                33334/udp

Is there something basic that I have overlooked ? should the interface=20
be set and left in
promiscuous mode to do what I require?

thanks pieter

--=20
VASTech PTY (LTD)
021 880 9807

Re: Soved problem receiving udp broadcasts

[Pieter]

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