perl udp broadcast

rosen4o has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: perl udp broadcast by Anonymous Monk on Jul 09, 2010 at 06:31 UTC
need to send packet from interface which doesn't have assigned ip address You can't communicate without an IP (like talking without a mouth). ?node_id=3989;HIT=UDP%20broad;re=N	[reply]
Re: perl udp broadcast by Khen1950fx (Canon) on Jul 09, 2010 at 07:02 UTC
Your English isn't very clear, but I think that you're looking for something like IO::Socket::INET. Here's an example of a server and a client by zentara that uses IO::Socket::INET.	[reply]
Re: perl udp broadcast by rowdog (Curate) on Jul 11, 2010 at 22:22 UTC
Are you saying that you get your address and gateway from a DHCP server and that you would like to send a UDP packet to the broadcast address? If so, then sure, check out IO::Socket::INET. If you want to do the above, but get the packet routed past the gateway, well, most routers won't pass a broadcast packet along so you're probably out of luck unless you can configure your gateway to pass it along, which is generally a bad idea.	[reply]
Re: perl udp broadcast by rosen4o (Initiate) on Jul 12, 2010 at 15:22 UTC
I want to make little broadcast config application. Clients will broadcast their ip addresses periodically server will listen for packets. The problem comes from there that I can't send broadcast packets without to have ip address on the network interface. Maybe Net::RawIP can help me???	[reply]
Re^2: perl udp broadcast by rowdog (Curate) on Jul 12, 2010 at 23:30 UTC
Sounds like a reverse DHCP. Since you don't have an IP address, you'll have to send at a lower level. I haven't used Perl for much below the layer of IP but if Net::RawIP doesn't work out for you Net::Frame and Net::Frame::Layer::Eth or Net::Write might be useful.	[reply]
Re^3: perl udp broadcast by rosen4o (Initiate) on Jul 14, 2010 at 13:47 UTC
Thanks I will try	[reply]
Re: perl udp broadcast by rosen4o (Initiate) on Jul 15, 2010 at 19:40 UTC
This modules have many dependencies. If I use this code I can send packet if even doesn't have gateway. Is there any way to send it on specific interface without ip on it. `$sock = new IO::Socket::INET( LocalAddr => '192.168.0.138', PeerAddr => '255.255.255.255', PeerPort => '9190', # Port the udp server listens on Proto => 'udp', Broadcast => 1 # Not sure if this is needed, I know the sockopt is ) \|\| die "[ERROR] $!\n"; $sock->sockopt(SO_BROADCAST, 1); print $sock "test\n";` [download]	[reply] [d/l]
Re^2: perl udp broadcast by Corion (Patriarch) on Jul 15, 2010 at 19:50 UTC
UDP is based on IP, so you can't send an UDP packet without an IP. Or rather, you'll have to construct a raw packet and send it on the raw interface.	[reply]