It's just local network information and some local filesystem info. Nothing really to secure
AFAICT from from the log, the only thing I see is that the multicast interface isn't getting properly set in the beginning. Is multicast enabled on the ETH4 NIC?
I'm not sure why the Panasonic is sending a stop packet. Are there other media servers that correctly send this content to the bluray player? If so, the only thing I can think of is comparing the packet traces between each media server and the player to see how the other media server responds to the player's restart request.
The whole UPnP/DLNA hand-shaking should be the most-straightforward part of this application, and every other client seems to work correctly in this regard with PMS, so I'm not sure where the glitch is...