1000 localhosts in DNS
dwing at cisco.com
Wed Jun 22 00:47:56 CEST 2011
> -----Original Message-----
> From: ipv6-ops-bounces+dwing=cisco.com at lists.cluenet.de [mailto:ipv6-
> ops-bounces+dwing=cisco.com at lists.cluenet.de] On Behalf Of Thomas
> Sent: Tuesday, June 21, 2011 1:22 PM
> To: ipv6-ops at lists.cluenet.de
> Subject: 1000 localhosts in DNS
> some discussions about ipv6- brokeness on client-site become obsolete
> as long
> on (web)server-site some people make bad jokes.
> From 1 0000 000 tested sites 1 000 have ::1 in AAAA.
I don't know how you chose those 1,000,000 hosts to check. I am checking
against Alexa's list, but my check this morning found only 100 (of
1 million) had ::1 or "::",
I like the ones that list "::", too,
# host listingdomains.com
listingdomains.com has address 220.127.116.11
listingdomains.com has IPv6 address ::
listingdomains.com mail is handled by 10 mx1.emailsrvr.com.
but fortunately "::" causes an immediate failure (on clients I tried)
so doesn't slow down access.
> What should be done?
> Hoping somebody reads the list and removes his entries?
> Does it make sense to search all webmasters and contact them?
I wouldn't worry about it. I just did DNS A and AAAA queries
using Alexa's list, and found 67 occurrences of IPv6 loopback:
> grep -E " ::1" a-records.txt | wc
67 536 5034
and for IPv4, found 226 occurrences of 127/8, 10/8, and 192.168/16,
which are also all inaccessible:
> grep -E " 127\.| 10\.| 192\.168\." a-records.txt | wc
226 1360 14361
So there is a reasonable amount of brokenness in the DNS --
even among Alexa's top 1 million sites. I have no idea how
or why those sites are on Alexa's list with broken DNS
I suppose someone could set up a DNS "nanny" service to
email the webmasters or DNS contacts at the offending sites.
But the problem affects bogus records for both A and AAAA;
it isn't exclusively an AAAA problem.
> PS: over 90% of the list-entries are also hosted at 18.104.22.168,
> whois says
> There’s no place like ::1
> Thomas Schäfer (Systemverwaltung)
> Centrum für Informations- und Sprachverarbeitung
> Schellingstraße 10 Raum J407A
> 80799 München ☎ +49/89/2180-9706 ℻ +49/89/2180-9701
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