SSDP packet forwarder
Like many people, I segment my home network such that IoT devices are on a different VLAN than my phone and laptop. Unfortunately, this breaks things like the Roku app because SSDP isn't meant to cross network boundaries.
I run this code on my OPNsense router to restore sanity to my home network. It works well with IPv4 traffic, but it has not been fully tested with IPv6. (Don't get me started on the irony of most IoT devices lacking support for IPv6.)
I'm not a network or protocol engineer, so don't assume this code is correct or bug-free.