I have a faulty app which is sending SSDP packets on the wrong interface. I made the dev aware of the problem and it will be fixed in the new release but in the mean time I was hoping I could use iproute2 as a stop-gap measure to shore up this problem.
Basically, any SSDP packets going out on interface 'eth0' I want to go out on interface 'br0' instead.
In case it matters, all of these packets are destined for 239.255.255.250