Greetings,

How would one go about routing multicast DNS packets (e.g. used for  
iTunes sharing neighbourhood discovery) between two different subnets  
sharing an OpenBSD router and secured by ipsec(4)?

So far from multicast(4) I have determined I need to /sbin/sysctl  
net.inet.ip.mforwarding=1 and I will most likely need to NAT the  
packets to alter their source address using pf(4) to fool the mDNS  
client into believing the peers are on the same subnet - but it's  
what comes inbetween about which I'm not certain.

Do I need to employ mrouted(8)?

This is my first foray into the bizarre world of IP multicasting...  
All the HOWTOs I've seen so far describing how to share iTunes  
libraries across different subnets (e.g. http://wiki.mt-daapd.org/ 
wiki/SSH_Tunnel ) employ an ssh tunnel and a client-side mDNS proxy  
but I can't help but feel that with a network under my control and  
OpenBSD routing everything there must be a more elegant solution?

Any assistance or advice will be appreciated.

Cheers,
Damon