Ilona wrote: > Hi, > I'm writing a program to forward udp broadcasts. > For protocols such as NNBS and Browser protocol, I need to have > multiple subnets appear as one broadcast subnet - for these udp ports. > For this to happen, broadcasts received on certain udp ports are > broadcast forward on the other interfaces. > Unfortunately for me, these broadcasts are received back at me, on the > interfaces on which they were sent out, > reulting in a loop. This is really only a special case of a more general problem: if there is a loop in the network itself, you will propagate these packets around the loop forever. One of the most simple approaches to this (you are essentially looking at the dense multicast forwarding problem) is reverse path forwarding (RPF). In RPF, each received packet from source S is rebroadcast only if it arrived on the interface upon which packets _to_ S would be routed - i.e., if they came along the reverse of the path to S. Other solutions are possible (as a brief search through the multicast routing literature will show) but few are as simple as RPF, or as easy to implement. > To block these broadcast loopbacks, I tried using the setsockopt > command, with the IP_MULTICAST_LOOP set to zero (hoping that, since > broadcasts are specific cases of broadcast, this would work) but to no > avail. > Does anyone have any ideas as to how this can be done? > Help, please! > Thanks > Ilona > > - > : send the line "unsubscribe linux-net" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Casey Carter Casey@Carter.net ccarter@uiuc.edu AIM: cartec69 - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
