Natting Multicast

hotrodowner · 05-15-2014, 07:12 AM

I have a need to change the multicast addresses coming in from a satellite receiver. All multicast streams come in constantly, so there is no need for IGMP. They come in on 224.0.255.0/24 and I need them to be 239.0.255.0/24. I first tried using scapy, but this was much too slow (it dropped 11 packets for each 1 packet it changed). Does anyone know of a way to do this in kernel space?

nikmit · 05-16-2014, 10:07 AM

iptables

hotrodowner · 05-17-2014, 06:14 PM

I was hoping to do it on OSI layer 2. ebtables seems to only be able to do natting of mac addresses (which seems silly, because iptables (a layer 3 firewall) can redirect tcp and udp ports, which is a layer 4 setting). I share my reciever with others and I don't want them finding some unpatched vulnerability in my natting device, and this is less likely when it is only addressable up to layer 2.