RFC 8305 Happy Eyeballs in OpenSSH

[Matthieu Herrb]

On Fri, Feb 23, 2018 at 12:32:38PM +0000, Kim Minh Kaplan wrote:
> Hello,
> 
> I use hosts that are dual stack configured (IPv4 and IPv6) and it
> happens that connectivity through one or the other is broken and
> timeouts. In these case connection to the SSH server can take quite some
> time as ssh waits for the first address to timeout before trying the
> next.
> 
> So I gave a stab at implementing RFC 8305. This patch implements part of
> it in sshconnect.c.
> 
> * It does not do section 3 (initiation of asynchronous DNS queries, a
>   SHOULD).
> * It does not do section 4 (sorting of resolved destination
>   addresses). That means it does not do the RFC 6724 address sort
>   which is a MUST.  The order is still the one from getaddrinfo(3).
> * It implements section 5 (initiation of asynchronous connection
>   attempts). It paces the connection attempts 250 milliseconds appart
>   as recommended. Once a connection attempt succeeds it cancels all
>   other initiated connections and ignores addresses not yet used.
> * It does not implement RFC 8305 for channels.c, that is port
>   forwardings do not use it.
>

Hi,

I like this. As I'm also running with dual stack machines both at work
and at home, and have sometimes issues with one of the stacks.

I'm running with this on my OpenBSD machines now. No problem noticed
so far.
-- 
Matthieu Herrb