Broadcast/ multicast support?

Tailscale user:
Do you intend to support broadcast / multicast within the TS network?

Support:
Thanks for this question!
Currently there is no support for broadcast or multicast due to the point-to-point nature of the connections. We do plan to add some multicast support in future to handle certain use cases, but there is no concrete timeline. If you can share examples of what you would like to do using broadcast/multicast then we can consider adding them to our list.

multicast support use cases:

  • Support Web Services Dynamic Discovery
  • Multicast DNS/DNS-SD service discovery

I recognise the point to point nature of the connections will be problematic due to software such as Avahi and WSDD usually ignoring those interface types.

Trying to forward all multicast traffic through the tunnel tends not to work well in mesh networks, but specific support for useful functions using multicast is likely at some point.

If you can share examples of what you would like to do using broadcast/multicast then we can consider adding them to our list.

A use case for us is with old peer-to-peer games, classic strategy games in particular all tend to use broadcasts to discover peers in-game. No broadcast support really hinders usage of tailscale for gaming (other legacy apps as well, though it’s harder to find examples of those)

Would be great for remote access to my Roon (https://roonlabs.com) server. Today I’m able to route multicast discovery packets over OpenVPN or WireGuard via udp-proxy-2020 (GitHub - synfinatic/udp-proxy-2020: A crappy UDP router for the year 2020 and beyond), but this is not possible with Tailscale.

1 Like

+1 on this. I’d like to use Tailscale with Roon and this is a blocker for that. This is actually a huge PITA and I’ve been looking for alternatives incessantly. Hope the Tailscale team works on this some time soon…

I’m surprised that udp-proxy-2020 isn’t working with Tailscale. Do you know why?

The problem as I recall, was that tailscale, unlike wiregard won’t forward the broadcast packets from the client application onto the VPN tunnel. Hence udp-proxy-2020 can’t forward them on the other end onto the LAN.

In theory, you could run udp-proxy-2020 on both ends of the tunnel, but the number #1 vpn client is iOS devices which that’s not an option since only one “VPN client” can be active at a given time and as best as I can tell, udp-proxy-2020 would have to register itself as a VPN on iOS to see the traffic from the client application.

We really need broadcasting so we can access license servers. Programs like ANSYS can only distribute licenses in this way… as far as I know

+1

I have a project that relies on UDP multicast for discovery of nodes in a cluster, and bring able to go beyond a local cluster using something like tailscale would be amazing.