Hope this isn’t too off topic, but does anyone happen to know if there’s any way to VPN with mDNS so that iTunes syncing and/or media sharing work remotely?
You generally need an Ethernet based VPN which you can do with openvpn.
Otherwise Avahi has a mode to allow reflecting (mdns traffic between two interfaces) on point to point interfaces and if you run that on the VPN server it may let mdns work from your vpn client to the local lan of the server. Will depend if your mdns implementation tries to query on the VPN interface though. Which again for avahi you can enable point to point on the client side. Unsure if you can do that on windows/Mac.
Otherwise Avahi has a mode to allow reflecting (mdns traffic between two interfaces) on point to point interfaces and if you run that on the VPN server it may let mdns work from your vpn client to the local lan of the server. Will depend if your mdns implementation tries to query on the VPN interface though. Which again for avahi you can enable point to point on the client side. Unsure if you can do that on windows/Mac.