Re: UDP broadcast address
Re: UDP broadcast address
- Subject: Re: UDP broadcast address
- From: Mark Hunt <email@hidden>
- Date: Wed, 11 Feb 2004 09:06:48 +0000
Peter
The devices I'm talking to are little microcontroller boxes - they
don't "do" DHCP, but set a 2.x.x.x IP address based on their MAC
address.
This means that in order to use them, the Mac has to be set to 2.x.x.x
as well, which is a pain.
They output serial data, which is broadcast over the network - the
serial channel number is encoded in the network packets. There's
generally no need to talk to them individually.
They seem to respond to an all 1's address as well as the subnet
broadcast.
I have seen my Mac send all to 1's, but I'm not sure why it did this -
it seemed to be random (or maybe I was using Open Transport at the
time).
I've just checked, and an OT app does send all 1's, so I could try
putting an OT port in my application - any problem with mixing OT and
sockets in the same app?
I'm sure there should be a way to do this with sockets, though Stevens
says:
"Most hosts ... convert the destination address to the subnet-directed
broadcast address of the outgoing interface", so maybe not.
I could use a raw port, but that means root privileges - doesn't it?
Thanks
Mark
>
Message: 5
>
From: Peter Sichel <email@hidden>
>
Subject: Re: UDP broadcast address
>
Date: Tue, 10 Feb 2004 09:06:28 -0500
>
To: NetworkProgramming Programming <email@hidden>
>
>
I didn't find IP_ONESBCAST in the Darwin sources either.
>
>
Another clue might be to look at what the Mac OS X DHCP client does.
>
I believe it generates packets to the all 1's address (according
>
to my DHCP Server log).
>
>
Can you say more about why you need this?
>
>
Kind Regards,
>
>
- Peter
>
>
=================
Mark Hunt
LSD FouthPhase
Birmingham
England
email@hidden
=================
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