[Bug 24828] Re: [Bug 24828] Re: IPv6 should be disabled by default

[Martin Hosken]

Dear Trent,
> Disabling IPv6 increaseing the throughput of your internet connection
> makes no sense and I think thats just circumstantial, sorry :)
>
> The place where it *does* make a difference is the speed of new
> connections, it seems that in some cases certain dns servers ignore
> requests for IPv6 records and so everytime you try to resolve an IPv6
> address it waits for them to timeout.
>   

It is worse than that. In the time it takes for the IPv6 DNS request to
fail the application times out on making its connection.
> These broken DNS servers should really be fixed, but the last point
> could work, not to bother looking up, guess it would fix some of these
> cases.
>   

It's not a question of the DNS server being dumb it's usually some cheap
ADSL router/modem that is sitting between the computer and a good DNS
server. Often configuring the router to pass a real DNS server address
to the dhcp client is enough to solve the problem. But not all routers
allow you to configure the dhcp server in them sufficiently.

So perhaps the real fix is to provide a way to turn off IPv6 DNS
requests. But I guess that is impossible without turning off IPv6 in
general. How much IPv6 takes off depends to a large extent on what MS do
with Vista, I would suspect.
> Could someone who experiences and is willing to let me login to their
> machine please contact me? I'd love to try this as its never really
> affected me.
>   
I'll send you directly, offline, a couple of tcpdump traces to compare.
One is dns request to the D-Link 504T ADSL modem/router and the other is
directly to a DNS server with packets merely routed by the modem.

-- 
IPv6 should be disabled by default
https://launchpad.net/bugs/24828