WireDuard On-Connect DNS Lookup Failure (tries UDP/53, does not fail over to TCP/53)

[Michael Hicklen]

Hi all,

I've noticed an issue today with WireGuard where it will fail to connect to a hostname when attempting to resolve DNS in a situation where UDP DNS lookups are disabled. This is reproducible by disabling UDP 53 egress, or by connecting to ExpressVPN first then trying to connect WireGuard to a server using a hostname.

This is an edge case, but I think it would be excellent if WireGuard were to attempt to fall back on TCP instead of failing out at the UDP lookup.

Note this is orthogonal to the endless requests for WireGuard to support TCP tunneling - that is not what I'm talking about here.

--
Michael Hicklen
michael at xfs.repair