[tor-relays] If the IPv6 ORPort can't be reached, will clients/relays fall back to the IPv4 ORPort?

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello. If a client or relay with IPv6 attempts to connect to a relay's IPv6 ORPort and receives no response, will it fall back to IPv4 or will it consider the relay unreachable? Assume that the directory authorities are able to reach the v6 ORPort. Is the behavior different if there is an explicit error returned, e.g. RST or an ICMPv6 no route to host? Regards, forest -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQQtr8ZXhq/o01Qf/pow+TRLM+X4xgUCal6ZDgAKCRAw+TRLM+X4 xgM7AP9xJhuSw8vYilYYbtzscuPLZk8BMY58gqPL2gocHYy/9wEAnduiOSjAeG6c 2yzboG7z5+HCV56tjIwXhuUTrprCmAY= =CQEB -----END PGP SIGNATURE-----