Routing failure when connecting to IPv6 address because of wrong default network interface

[cyberduck]

7ee63cc created the issue

Connection to an IPv6-only server is impossible when using the Mac version. The result is always: 'No route to host'.

I can ping6 the IPv6 server, so there is a working route.

Additional information:

• reproducible with an IPv6 address or IPv6-only hostname (only AAAA record in DNS)
• reproducible using the quick connect bar, and also when using a bookmark entry
• FTP and SFTP (other types not tested)
• Windows version 4.7 is working
• Mac version 4.3.1 is working!
• Mac version 4.4 and up are not working

[cyberduck]

@dkocher commented

Add test in 610dcd9.

[cyberduck]

@dkocher commented

Add test in 0ff86e2.

[cyberduck]

@dkocher commented

~~ Can you try to append the interface (such as %en0) to the address as in fe80::c62c:3ff:fe0b:8670%en0.~~ 

[cyberduck]

@dkocher commented

Replying to [comment:5 dkocher]:

~~ Can you try to append the interface (such as %en0) to the address as in fe80::c62c:3ff:fe0b:8670%en0.~~ 
I suppose an interface identifier makes no sense with a non link local address.

[cyberduck]

@dkocher commented

More tests in 47c2f1e, f9e760e and e2963e7.

[cyberduck]

@dkocher commented

I cannot reproduce this issue. Please share more details of your setup to reproduce.

[cyberduck]

7ee63cc commented

Replying to [comment:8 dkocher]:

I cannot reproduce this issue. Please share more details of your setup to reproduce.

See this Screencast:
http://screencast.com/t/vw91SFB3

In the video I show you that I can successfully 'ping6 ftp6.netbsd.org' and 'ftp ftp6.netbsd.org', but in Cyberduck the result to the same server is always: 'No route to host'. This is just an example, it is like that for any IPv6 only host on internet.

Hope this helps.

[cyberduck]

@dkocher commented

Add test in a3ee5e2 to resolve public IPv6 only address.

[cyberduck]

@dkocher commented

Add failing test reproducing the issue in 7c0e379.

[cyberduck]

@dkocher commented

This looks to be an issue with the wrong default interface being selected. On my machine if I disable awsdl0 and the vmnet* interface from VMWare the proper en0 interface gets selected and routing succeeds.

sudo ifconfig awdl0 down

[cyberduck]

@dkocher commented

Some reference

AWDL (Apple Wireless Direct Link) is a low latency/high speed WiFi peer-to peer-connection Apple uses for everywhere you’d expect: AirDrop, GameKit (which also uses Bluetooth), AirPlay, and perhaps elsewhere. It works using its own dedicated network interface, typically “awdl0".

[cyberduck]

@dkocher commented

In 2f840be.

[cyberduck]

7ee63cc commented

Great! I will test it as soon as the snapshot build arrives.

[cyberduck]

@dkocher commented

Replying to [comment:16 richardvd]:

Great! I will test it as soon as the snapshot build arrives.
A new snapshot build has been pushed.

[cyberduck]

7ee63cc commented

I just installed the latest snapshot version 4.8 (17573). No change, it still results in 'no route to host' in this situation.

It does work after sudo ifconfig awdl0 down, so the application still seems to select the wrong interface.