Re: Python 2 and test/vm/netbsd

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 10/18/19 4:29 PM, Eduardo Habkost wrote:
> On Fri, Oct 18, 2019 at 12:44:39PM +0200, Gerd Hoffmann wrote:
>>    Hi,
>>
>>>> Running with V=1, I see packages being downloaded at reasonable speeds, but
>>>> there's a huge interval (of various minutes) between each package download.
>>>
>>> I've found the cause for the slowness I'm seeing: for each file
>>> being downloaded, the guest spents at least 75 seconds trying to
>>> connect to the IPv6 address of ftp.NetBSD.org, before trying
>>> IPv4.
>>
>> Ah, that nicely explains why it worked just fine for me.  First, I have
>> a local proxy configured so the installer isn't going to connect to
>> ftp.NetBSD.org directly.  Second I have IPv6 connectivity.
>>
>>> I don't know if this is a NetBSD bug, or a slirp bug.
>>
>> Both I'd say ...
>>
>> First, by default slirp should not send IPv6 router announcements
>> to the user network if the host has no IPv6 connectivity.
>>
>> Second, the recommended way to connect is to try ipv4 and ipv6 in
>> parallel, then use whatever connects first.  Web browsers typically
>> do it that way.  wget and curl don't do that though, they try one
>> address after the other, and I guess this is where the delay comes
>> from ...
> 
> In addition to that, the connect() error should be generating a
> ICMP6_UNREACH message, and I'd expect the NetBSD guest to notice
> it instead of waiting for timeout.

Is this missing in SLiRP?