[dns-operations] CloudFlare public DNS IPv6 anycast high latency from HE in USA?

Viktor Dukhovni ietf-dane at dukhovni.org
Tue Feb 23 21:49:24 UTC 2021

On Tue, Feb 23, 2021 at 11:29:17AM +0100, Teun Vink wrote:

> On 22 Feb 2021, at 23:33, Viktor Dukhovni wrote:
> > For CloudFlare public DNS IPv6 addresses:
> >
> > 	2606:4700:4700::1111
> > 	2606:4700:4700::1001
> >
> > I see unexpectedly high latency from two distinct networks in the USA,
> > where the common factor is plausibly an early transit via Hurricane
> > Electric.  [...]
> We observed similar issues here (AS12859, NL). As far as I can tell, HE 
> started advertising the prefixes containing Cloudflare’s DNS servers 
> this weekend via public IXPs (AMS-IX, NL-ix, DE-CIX), causing traffic 
> towards those destinations to take a nice detour across the Atlantic. We 
> have changed some routing policies to lower preference on routes offered 
> by HE and contacted CloudFlare to setup more direct peering sessions.

Thanks, so I was not alone.  Whatever was going on yesterday, is *much*
better today.  I now see:

    isi.edu LA: rtt min/avg/max/mdev = 1.165/1.388/1.511/0.158 ms
    VZ->HE NYC: rtt min/avg/max/mdev = 6.587/6.874/7.291/0.302 ms

which I rather prefer to 200+ms. :-)


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