Consider TAP mode, not just TUN for 6bed4router

[vanrein]

In TAP mode, a 6bed4 interface could plug into a bridge, alongside a public IPv4 address.

• This would make the -l argument unnecessary
• Multiple 6bed4router processes might be created to accommodate multiple IPv4 addresses
• One or more IPv6 address on the interface might be used as -L and/or -R arguments

Look at what Tayga does; it has an interface that continues to exist (and be configured) in spite of the daemon going up and down. This provides better resilience. Plugging into a bridge can further enhance that.

[vanrein]

The MAC address to use would be as described in the specification, and involves the bound-to IPv4 address and UDP port. This makes complete sense, for uses such as BROUTING where certain traffic is pulled towards a MAC address for delivery.